Russian Chemical Reviews 68 (1) 39 ± 53 (1999) Recyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives { V P Litvinov Contents I. Introduction II. Recyclisation of three- and four-membered rings III. Recyclisation of five-membered rings IV. Recyclisation of six-membered rings V. Conclusion Abstract. Published data on recyclisation reactions of carbo- and heterocycles with participation of malononitrile and recyclisation of compounds containing a malononitrile fragment or fragments with malononitrile as a synthon are surveyed, described system- atically and analysed. The bibliography includes 206 references. I. Introduction Recyclisation of carbo- and especially heterocyclic compounds occupies an important place in organic chemistry.Recyclisation in the presence of various nucleophilic, electrophilic or dipolar reagents occurs as opening of the ring in the initial molecule and its subsequent closure. This process is often accompanied by ring expansion or contraction, introduction of a heteroatom in the ring or its replacement by another heteroatom, etc. Nevertheless, from the preparative viewpoint, all these complex transformations occur during a one-stage reaction, which makes possible relatively easy synthesis of compounds that are difficult to obtain by other methods or modification of heterocyclic fragments in complex, including natural, molecules. The latter is fairly important for the synthesis of new biologically active products.At present, a large number of transformations of this type are known; they include name reactions, for example, the Yur'ev, Zincke ± Konig and Hafner reactions, the Dimroth, Boulton ± Katritzky, Cornforth and Kost ± Sagitullin rearrangements, etc. The problem of recyc- lisation is considered in numerous publications and reviews (see, for example, Refs 1 ± 24). Malononitrile 1, containing highly reactive methylene and cyano groups,25 is of special interest as a reagent for recyclisation of carbo- and heterocyclic compounds. In this review, we consider recyclisation reactions with participation of malononitrile and its derivatives including carbo- and heterocyclic compounds with vicinal cyano groups. Primary attention is paid to the synthetic potential of these reactions and less space is given to the reaction mechanisms, because the data on the mechanisms are quite limited and often contradictory.V P Litvinov N D Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Leninsky prosp. 47, 117913 Moscow, Russian Federation. Fax (7-095) 135 53 28. Tel. (7-095) 135 88 37 Received 12 March 1998 Uspekhi Khimii 68 (1) 45 ± 60 (1999); translated by Z P Bobkova #1999 Russian Academy of Sciences and Turpion Ltd UDC 547.7/8 39 39 41 45 50 II. Recyclisation of three- and four-membered rings In 1983, a group of German scientists found that cyclopropene derivatives 2 react with the malononitrile anion, generated by treatment of malononitrile with sodium methoxide in methanol, to give functionally substituted cyclopentadienes 3.Bicyclic derivatives 4 were postulated as intermediates in this reaction.26 NC NH Ph CO2But MeONa Ph CO2But MeOH + CH2(CN)2 1 R R 2 R R4 NC NH2 Ph CO2But R R 3 (49% ± 64%) R=Me, Ph. Cycloaddition of N-cyclohexenylpyrrolidine 5 to 2,2- dimethyl-1,1-cyclopropanedicarbonitrile 6 has been reported.27 The reaction follows an SN2 mechanism and yields adduct 7. On partial hydrolysis, this product rearranges into spiro compound 8, which is further hydrolysed to give 5-(4,4-dimethyl-2-oxocyclo- pentyl)pentanoic acid 9. Me N Me C6H4Me2 95% EtOH N + D, 19 h CNCNMe 150 8C, 31 h NC CN Me 6 5 7 (47%) O O Me (CH2)4CO2H H3O+ Me Me CN Me H2N 9 (83%) 8 (91%) The reactivity of substituted tetracyanocyclopropanes has attracted considerable attention of researchers in recent years.Thus it was found that treatment of 3,3-phthaloylcyclopropane- 1,1,2,2-tetracarbonitrile 10 with nucleophiles (alcohols or ketox- { This review is dedicated to the memory of Professor Yu A Sharanin.40 imes) induces recyclisation of the cyclopropane fragment in 10 and results in the formation of 2-alkoxy-2-(2-alkoxycarbonylphenyl)- 5-amino-4-cyano-3-dicyanomethylene-2,3-dihydrofurans 11.28,29 NC CN CN O NC NC OR RO7 NC H2N CN O ORO2C 11 10 . R=Me, Et, (CH2)2OH, N=CMe2, N Unlike the cyclopropane 10, 3,3-diacetylcyclopropane- 1,1,2,2-tetracarbonitrile 12 reacts with alcohols or ketoximes in the presence of catalytic amounts of the corresponding sodium alkoxides or oximates with retention of the cyclopropane ring to give substituted 3-oxabicyclo[3.1.0]hexane-1,6,6-tricarbonitriles 13.28,30 However, when a twofold excess of the catalyst is used, 2,3-dihydrofuran derivatives 14 are formed under similar con- ditions. NC CNCOMe NC RO Me CN O NC OR H2N Me RO7 O13 Me NC NC CN NC CN O 12 Me H2N OR O14 R=Me, Et, N=CMe2, N=CMeEt, N=CMeBu, (CH2)2OH, ., N N The cyclopropane ring is also retained when substituted pyrazoline-4-spirocyclopropanetetracarbonitriles 15 are treated with alcohols and ketoximes under the same conditions; this reaction affords adducts 16.31 CN O OR0 CNO CN NC NR R0O NR R0O7 +R0OH N N N NC Me CN Me 15 ., N H2N16 R=Pri, Ph; R0 =Me, Et, N=CMe2, N=CMeEt, N When ethyl pentacyanocyclopropanecarboxylate 17 is made to react with alcohols in the presence of an equimolar amount of the corresponding alkoxide, it undergoes recyclisation to give 5,5- dialkoxy-2-amino-4-dicyanomethylene-2-pyrroline-3-carboni- triles 18. The formation of a stable intermediate, sodium penta- cyanopropenide 19, was noted.32 CN CN 7 NC CN CN RO7 +RO7Na+ CO2Et NC Na+ NC CN NC CN 19 17 NC NC Na+ 7 NC NC CN CN H2SO4 OR OR H2N H2N N OR OR NH18 R=Me, Et. V P Litvinov 2H-Pyrazolo[3,4-b]pyridines 21 have been prepared by recyc- lisation of tetracyanocyclopropanes 20 involving phenylhydra- zine.33 R NC R NH2 CNCN PhNHNH2, MeOH 125 8C, 24 h BuOH D, 8 h NH NCH2N NC CN 21 NPh R NH2 NC NPh N H2N N20 R=Me, Et, Ph, 4-ClC6H4, 4-NO2C6H4.The reaction of 3-dicyanomethylene-1,2-diphenylcycloprop- 1-ene 22 with 3,4-dihydroisoquinolines 23 in ethanol is accom- panied by recyclisation giving rise to 4-dicyanomethylene-2,3- diphenyl-4H-2,3,6,7-tetrahydropyrido[2,1-a]isoquinolines 24 in 73%± 78% yields.34 Refluxing of the compound 22 with isoni- triles 25 in acetonitrile results in the formation of 4-dicyano- methylene-4H-cyclopenta[2,3-b]imidazole derivatives 26 in 43%± 58% yields.35 CN Ph Ph N CN N + Ph R CN NC CH2R 23 22 Ph 24 R=H, Me, Ph. CH2RR Ph N N Ph 22+RCH2N=C 25 CN NC 26 R=Ph, CO2Et.Various three-membered heterocycles, oxiranes,1,36 thiir- anes 1,36 ± 38 and aziridines,38,39 can also undergo recyclisation on treatment with nucleophiles. Thus it was found that the reaction of oxiranes 27 with malononitrile in the presence of sodium ethoxide in ethanol occurs as recyclisation yielding 2-amino-4,5- dihydrofuran-3-carbonitrile 28.40 ± 42 CN R3 R3 EtONa R2 R1 R2 EtOH NH2 + CH2(CN)2 1 R1 O27 O28 R1=H, Me, Et, Ph; R2, R3=H, Me. In the case of oxiranes 29, recyclisation proceeds via acyclic intermediates 30, which were treated with malononitrile after isolation. This afforded 2-amino-4-nitromethyl-4,5-dihydro- furan-3-carbonitrile 31 in yields of up to 60%.43 ± 45 R CH2NO2 RCHCH CHNO2 Et3N 1 MeOH OH O 30 29 NC CH2NO2 R H2N O31 R=H, Me.2-Methoxy-2,3-diphenyloxirane 32 recyclises in the presence of sodium malononitrile giving rise to 2-amino-4,5-diphenyl- furan-3-carbonitrile 33.46Recyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives CN Ph Ph PhOMe O Ph NH2 32 O33 H NC CH2Br The g-iminolactone 35 has been synthesised by treatment of the oxirane 34 with potassium malononitrile in tert-butyl alco- hol.47Me Me Me HN Me O34 O35 It has also been reported48, 49 that recyclisation of 2,2-dicya- nooxiranes 36 in the presence of amidines 37 affords 4-amino- imidazole-5-carbonitriles 38. R CN NH NPh R CNCN + R0 NH O O PhN NH2 36 37 R0 HN H2N N N NC R0 NC R0 N N RHC Ph 38 OH Ph Thiiranes also enter into recyclisation reactions.1, 38, 42, 50 ± 52 For example, thiiranes 39a ± c react with malononitrile in the presence of sodium hydride in DMSO giving 2-amino-4,5-dihy- drothiophene-3-carbonitriles 40a ± c in 50%± 62% yields. Note that in the case of the thiiranes 39a,b, ring opening occurs in conformity with Krasuskii's rule, while in the case of 39c, the ring opens against this rule.38,50 CN R2 R2 R1 1, NaH DMSO R1 NH2 S 39a ± c S 40a ± c R1=H: R2=H (a), Me (b), Ph (c).Recyclisation reactions for three-membered nitrogen-contain- ing heterocycles have been reported.42, 52 ± 54 The reaction of aziridines 41 with malononitrile in the presence of sodium hydride affords different products depending on the reaction conditions and the ratio of the reactants.42 When the compounds 1 and 41 are taken in equimolar amounts, 2-amino-1-(toluene-p-sulfonyl)-4,5- dihydropyrrole-3-carbonitrile 42 is formed.The reaction with a twofold excess of the initial aziridine 41 (ButOK, 10 8C) yields spiro compound 43, whereas the use of a twofold excess of malononitrile and an increase in the reaction temperature to 100 8C results in the formation of 2,3-dihydropyrrolo[2,3-b]pyr- idine 44. CN NaH 710 8C NH2 NTs 42 HN Ts N 1 N N ButOK 10 8C Ts 43 NH Ts 41 NH2 NC ButOK 100 8C N H2N Ts N44 41 Recyclisation of four-membered heterocycles with participa- tion of malononitrile is also known.Thus the reaction of 2-oxe- tanone 45 with malononitrile in the presence of sodium hydride affords 2-amino-3-cyano-6-methyl-4-pyrone 46.55 O O CN 1, NaH O H2C Me NH2 45 O46 Treatment of 1-ethoxycarbonyl-5-oxo-4-oxaspiro[2.3]hexane 47 with malononitrile under similar conditions gives rise to a mixture of cyclopentenone 48 and 2-amino-4-pyrone 49 (yields 49% and 24%, respectively).56 1-Dimethoxyphosphoryl-1- methyl-5-oxo-4-oxaspiro[2.3]hexane 50 reacts with malononitrile under the same conditions to afford 2-amino-3-cyano-6-(2-dime- thoxyphosphorylpropyl)-4-pyrone 51 in 58% yield.56 CO2Et O HO NC 1, NaH CO2EtO + THF O HH H O CO2Et H2N 49 47 O48 O O NC Me 1, NaH Me P(OMe)2 O THF O P(OMe)2 H2N O O 51 50 III.Recyclisation of five-membered rings Recyclisation of tetracyanocyclopentanes 52 has been reported.57, 58 Depending on the reaction conditions, they are transformed into 2-dicyanomethylenepyrrolidines 53 or tetracya- nopiperidones 54. R1 CN NC PriOH Et3N R1 CN 2 NC NNR2 53 NHNR22 R1 CN NCNC CN 52 KMnO4 HCl, H2O O N CN CN CN 2 NR2 54 R1=Me: R2=Me, Et; R1=Pr, R2=Me. A scheme for the transformation of 2-dicyanomethylenein- dane-1,3-dione 55 into salts 56 has been proposed.59 The trans- formation is attained by refluxing 55 in acetonitrile in the presence of lithium iodide or methyltriphenylphosphonium iodide or by stirring it in dry THF with finely divided sodium. The reaction scheme includes a single-electron transfer in the indanedione 55 resulting in symmetrical radical anion 57, which cyclises to give spirocyclopropane intermediate 58.The rearrangement of the compound 58, accompanied by cyclopropane ring opening, and subsequent cyclisation result in the formation of cyclopropane intermediate 59. This compound also recyclises to afford salts 56. Treatment of the lithium or methyltriphenylphosphonium salt 56 with concentrated hydrochloric acid gives 2,3-dicyano-1,4-naph- thoquinone 60 in 65% and 40% yields, respectively.59V P Litvinov 42 O O CN a or b 7 under similar conditions being thus converted into 2-acetyl-5- amino-3-methylcyclopentadiene-1,1,4-tricarbonitrile 70 in 60% yield.67 C N .CN Me CN MeOC 57 O N O 55 H+ NC 1, NaOH N O O N7 Me Me EtOH 7 C Me Me CN (CN)2CH O O67 N . .Me Me 7 CN CN NHCOMe NC NC NH2 O59 O 58 O O7 Me Me N (CN)2HC (CN)2HC CN CN N68 HCl Me NC NH2 CN CN . 60 56 O O NC Me HN (a)M+I7, MeCN, D,M =Li, Ph3PMe; (b) Na, THF, 20 8C, 48 h. CN Me NC Me N COMe MeOC Me H2N CN NC O69 70 The review on molecular rearrangements of five-membered heterocycles11 published in 1984 presents virtually no data on recyclisation with participation of malononitrile or recyclisation of heterocyclic systems containing malononitrile fragments. Meanwhile, an original pathway to aminoazulenes 61 consisting in recyclisation of lactones or iminolactones, 2H-cyclohepta[b]- furan derivatives 62, on treatment with methylene active nitriles, including malononitrile, had been reported in the litera- ture.36, 60 ± 63 R R 1, EtONa or X NH2 1, ButNH2 It has been noted 68 ± 71 that isoxazoles 71 recyclise to give 2-amino-4H-pyran-3,5-dicarbonitriles 72.Opening of the isoxa- zole ring in the compound 71 under the action of an aldehyde and EtONa in ethanol gives rise to substituted nitriles 73. The subsequent nucleophilic attack on the compounds 73 by malono- nitrile followed by cyclisation of the Michael adducts 74 affords aminopyrans 72.69 O 62 61 CN R2 R2 CN X=O, NAc; R =CO2Et, COMe. CN NC 1 R2CHO N R1 HN NC O 71 R1 O R1 O74 73 R2 CN NC 2,5-Disubstituted pyrrolidine-3,3,4,4-tetracarbonitriles 63 react with aromatic amines to give 2-aminopyrrole-3,4-dicarboni- triles 64.64 Depending on the ratio of the reactants, the reactions of the compounds 63 with primary alcohols in the presence of KOH yield either 3,4-dicyanopyrroles 65 or substituted 3H-pyrro- lo[2,3-d]pyrimidines 66.65, 66 R1 O H2N CN NC NC CN NC CN 72 NC CN R0NH2 NC 140 8C 7HCN R NH2 R R R NH2 R1=Me: R2=Ph, 4-MeC6H4, 4-MeOC6H4, But; R1=Ph: R2=Pri, But, CHEt2.NR0 HN NR0 63 64 R=Ph; R0 =Ph, 3-MeC6H4. CN NC In turn, when fused isoxazoles 75 and 76 are made to react with malononitrile in the presence of triethylamine, the corre- sponding annelated 2-amino-3-cyanopyridine 1-oxides 77 and 78 are formed in high yields.70 ± 72 O O N CHR R0O Me CN Me NH N N 1, Et3N 65 O 63 R0OH KOH NH2 N CN N O N N O NH2 RH2CN O OR0 Me 75 Me77 N R R3 R3 N66 CN R2 R2 1, Et3N ; R0 =Me, Et, Pr.R=Ph, 4-BrC6H4, 4-FC6H4, 4-MeC6H4, O O N N NH2 R1 O R176 78 R1=H, Me; R2=H, NO2; R3=H, Cl, NO2. 4-Acetyl-2,5-dimethyloxazole 67 also reacts with malononi- trile with recyclisation of the oxazole ring. This reaction results in the formation of 3-amino-6-dicyanomethyl-2,4-dimethylpyridine- 5-carbonitrile 68 in 33% yield. 5-Acetyl-2,4-dimethyloxazole 69, which is an isomer of the compound 67, reacts with malononitrileRecyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives Recyclisation of 4-aminothiazolin-2-ylidenemalononitriles 79, prepared from 4-aminothiazoline-2-thiones 80, in the presence of sodium ethoxide in ethanol giving substituted 3,5-diaminothio- phene-2,4-carbonitriles 81 has been described.73 H2N H2N NR2 Me2SO4 NR2 MeSO74+ 1, Et3N MeOH MeCN S R1OC SMe R1OC S S 80 CN H2N H2N NR2 EtONa CN EtOH R1OC NHR2 NC CN S79 S 81 (30% ± 64%) R1=OEt, NH2; R2=Me, Ph, Bn, CH2CH=CH2.Substituted 4-dicyanomethylenethiazolidin-5-ones 82 form complexes 83 with morpholine. Hydrolysis of these complexes with hydrochloric acid affords pyrrolo[3,4-c]pyridine derivatives 84, whereas their interaction with NaOHfollowed by acidification gives rise to furo[3,4-c]pyridine derivatives 85.74 CN CN R2 7 O HN O NC O H NC R2 S H +N O S O RN1 R1 N O 82 83 R2 S HN H+ NR1 O O CN84 O H H2N O CN O N OH7 H+ NaO CN NaO S HO S HO NR1 R2 R2 NHR1 H2N H O O N O NR1 R2 85 S R1=Ph, 4-MeC6H4, 4-MeOC6H4; R2=Ph, 4-MeC6H4.It was also shown that 2-methylthio-5,7-diphenyl-1,3,4-oxa- diazolo[3,2-a]pyridinium iodide 86 reacts with malononitrile in ethanol in the presence of triethylamine to give 2-amino-5,7- diphenylpyrazolo[1,5-a]pyridine-3-carbonitrile 87.75 Ph Ph 1, Et3N CN EtOH N Ph O Ph N + I7 N N SMe NH2 87 (72%) 86 2-Methylthio-5-phenyl-1,3,4-thiadiazolo[3,2-c]-4-quinazoli- nium iodide 88 reacts with malononitrile in a similar way, with elimination of one heteroatom from the five-membered ring. Thus it was shown that the salt 88 reacts with malononitrile in dry 43 acetonitrile in the presence of triethylamine to give 2-amino-3- cyanopyrazolo[1,5-c]quinazoline 89.76 When potassium triethyl- amine is replaced by potassium tert-butoxide, a mixture of the pyrazoloquinazoline 89 and 3,4-dihydroquinazoline 90 is formed.76 Ph N 1, Et3N MeCN N N Ph N I7 NH2 N+N NC 89 (56%) N Ph SMe S 88 1, ButOK NH + 89 (54%) MeCN NC CN 90 (24%) Recyclisation of 1,3-oxathiolium salts 91 on treatment with malononitrile has been used successfully in the synthesis of func- tionally substituted thiophenes 92.36, 77 ± 81 In the general form, the mechanism of this reaction includes the attack on the 2-position of the salt 91 by the malononitrile anion to give adduct 93.The subsequent cleavage of the ring at the C(2) ± S(3) bond in the compound 93 gives intermediate 94, which then cyclises according to the Thorpe reaction pathway to give imine 95; this product isomerises into more stable 3-aminothiophene 92.S 7 S X7 CH(CN)2 + CH(CN)2 R2 R1 R1 O O 91 R2 93 NC CN NH NC COR1 R2 R2 R1COCH2S S 95 94 NC NH2 COR1 R2 S 92 ; R1=Ph, 4-BrC6H4, 4-ClC6H4,O O R2=Ph, 4-MeOC6H4, 4-Me2NC6H4. 1,3-Oxathiolidene-2-immonium salts recyclise in a similar way to give functionally substituted thiophenes.81,82 The reaction of 3-methylthio-1,2-dithiolium iodides 96 with ylidenemalononitriles 97 in dichloromethane in the presence of triethylamine has been shown83 to afford dithiolylidenenitriles 98 and recyclisation products � 2-iminothieno[3,2-b]thiopyran-3- carbonitriles 99.R2 SMe R3 CN Et3N + + CH2Cl2 S R1 CN Me I7 S 96 97 R3 R3 NC S S S CN R1 + R1 HN CN R2 R2 S99 98 R1=Ph, SMe, 4-MeOC6H4; R2=H, 4-MeC6H4; R3=Ph, 4-MeOC6H4.44 The reaction of iodide 100 with malononitrile in the presence of triethylamine in chloroform is also accompanied by recyclisa- tion of the dithiole fragment. Simultaneously, ring expansion occurs and 2-imino-4-(N-methylanilino)-2H-[1,4]dithiapino- [2,3-b]indole-3-carbonitrile 101 is formed in 83% yield.84 NMePh + S NMePh S 1, Et3N I7 CN CHCl3 S S NH NHNH 101 100 1,3,4-Dithiazolium perchlorates 102 react with malononitrile in the presence of a base (Et3N, NaH, pyridine, g-picoline) in EtOH, THF, CH2Cl2 or MeCN.Depending on the substituent at the C(5) atom, the base used and the ratio of the reactants, this gives 4-amino-2-(1-cyano-2-dialkylamino-2-sulfanylvinyl)-6-phe- nylpyrimidine-5-carbonitriles 103, 2-dicyanomethylene-5-phenyl- 1,3,4-dithiazole 104 or substituted 1,3-butadiene 105.85HS H2N R N R=NMe2, NEt2 NC CN N103 Ph ClO7 Ph Ph 4 CN S S + R 1, B R=NMe2, SMe 7RH N N CN S104 S 102 CN R CN R=NEt2 HS 7PhCN,7S8 CN H2N105 B is a base. The pathway of the reactions of 1,3-dithiolium perchlorates with malononitrile also depends substantially on the nature of the substituents in the heterocycle and the solvent used. For example, the reaction of 2-diethylamino-4-phenyl-1,3-dithiolium perchlo- rate 106a with malononitrile in the presence of a weak base (g-picoline) results in the formation of 2-dicyanomethylene-4- phenyl-1,3-dithiole 107, whereas in the presence of a strong base (triethylamine), 3-amino-5-diethylamino-2-thiobenzoylthio- phene-4-carbonitrile 108a is formed.85 Ph CN S CN Ph S S107 1, B + CN H2N S 4 R ClO7 106a,b PhC R S S 108a R=NEt2 (a), NMe2 (b).However, when 2-dimethylamino-derivative 106b is used as the substrate, 1,3-dithiole 107 is formed in the presence of the strong base, triethylamine. Similarly, the final products formed in the reaction of 4,5- diphenyl-1,3-dithiolium perchlorates 109 with malononitrile depend on the reaction conditions; this reaction can yield (in various proportions) 2-dicyanomethylene-4,5-diphenyl-1,3- dithiole 110, 2-amino-5,6-diphenyl-1,4-dithiine-3-carbonitrile 111 and 4-amino-2-dicyanomethylene-5,6-diphenyl-2H-thiine-3- carbonitrile 112.85 V P Litvinov Ph Ph CN S S + + NR2 1, B 20 8C CN Ph ClO7 Ph 4 S110 S 109 NH2 CN Ph Ph S NH2 + + CN S Ph CN Ph S 111 CN 112 O.NR2=NEt2, N The reaction of 3,5-diphenyl-1,2,4-dithiazolium perchlorate 113 with malononitrile on refluxing in THF in the presence of sodium hydride is accompanied by recyclisation and gives 2,6- diphenyl-4-sulfanylpyrimidine-5-carbonitrile 114 in 92% yield.86 Ph CN S S + N 1, NaH Ph THF N Ph ClO7 SH Ph 4 N 114 113 2-(2-Hydroxyphenyl)-4-dicyanomethylene-4H-1,3-benzox- azine 116 and 5-imino-2-(2-hydroxyphenyl)-1-benzopyrano- [4,3-d]pyrimidine-4-thione 117 have been synthesised by recyclisa- tion of 1,2,4-dithiazolidine 115 involving malononitrile in the presence of NaF (refluxing for 2 min in a 1 : 1 DMSO: Pr2O mixture).87 NC O S S CNS 1, NaF NH NH O 115 OH HO CN NC N N OH + OH NH O O 116 (45%) 117 (4%) NH S On fusion with malononitrile (15 min, 90 8C), 2-butylbenzoi- midazo[1,2-d][1,2,4]thiadiazol-3(2H)-one 118 undergoes recycli- sation with elimination of isocyanate to give 3-imino-2,3- dihydrobenzoimidazo[2,1-b][1,3]thiazole-2-carbonitrile 119.88, 89 NH O 1 N N 90 8C, 15 min NBu CN N S S 119 (46%) N118 In a series of studies,90 ± 93 it has been found that benzofurox- ans recyclise on treatment with malononitrile giving rise to substituted 2-amino-3-cyanoquinoxaline N,N-dioxides.Recycli- sation of benzofuroxan-15-crown-5 120 during the reaction with malononitrile in DMF in the presence of triethylamine, resulting in the formation of 2-amino-3-cyanoquinoxaline N,N-dioxide 121,93 can be cited as an example. O O O N NH2 N O O 1, Et3N O O O DMF O O N CN N O O O 120 121 ORecyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives IV. Recyclisation of six-membered rings For six-membered carbocycles containing a malononitrile frag- ment, base-induced recyclisation of 1-amino-1,3-cyclohexadiene- 2,6,6-tricarbonitriles 122, resulting from dimerisation of alkylide- nemalononitriles, has been reported.This reaction yields 2-dicya- nomethylene-1,2-dihydropyridine-3-carbonitriles 123 and involves intermediate formation of cis(trans)-2-amino-1,3,5-hex- atriene-1,1,3-tricarbonitriles 124.94 ± 101 CN H2N R1 NH2CN NC CN NC Et3N CN CN CN H R2 R1 R2 R1 NH 122 CN R2 123 H124 R1=Ph, 4-MeC6H4; R2=Ph, 4-FC6H4, 4-ClC6H4, cyclo-C3H5. The formation of acetylaminothiophene 125 in a low yield in the recyclisation of hexa-1,3-diene 126 upon refluxing with morpholine polysulfide in ethanol for 4 h has been described.102 NH2CN CN Me NC O HNS8, D NHCOMe EtO2C EtO2CH2C CN CN CN S 125 (1.5%) 126 Recyclisation of six-membered heterocycles with participa- tion of malononitrile possesses a substantially greater synthetic potential.First of all, mention should be made of recyclisation of heterocyclic compounds to carbocyclic compounds. For example, recyclisation of 2,4,6-triphenylpyrylium salt 127 during its reac- tion with malononitrile in tert-butyl alcohol in the presence of potassium tert-butoxide affords 2-amino-3-cyano-4,6-diphenyl- benzophenone 128, which is difficult to obtain by other methods, in a high yield.103 ± 106 O Ph Ph PhC 1, ButOK BF74ButOH Ph Ph O +Ph H2N CN 127 128 Later, this reaction was used to prepare 2-amino-3-cyano-4- methyl(or phenyl)-6-piperidylaceto(or benzo)phenones 129 107 and 2,4,6-triphenylbenzonitrile 130 108 from pyrylium salts 131 and 2,4,6-triphenylthiapyrylium perchlorate 132. R R 1, ButOK + CN N O N ButOH R NH2 4 ROC129 ClO7 131 R=Me, Ph.Ph Ph 1, Pri2NEt ClO74+ EtOH Ph Ph Ph Ph S 132 CN 130 The synthesis of 4-amino-2-benzoyl-1-phenylfluorene-3-car- bonitrile 133 in 89% yield by the reaction of 2,4-diphenyl-5H- indeno[2,1-b]pyrylium perchlorate 134 with malononitrile in ace- tonitrile in the presence of piperidine has been reported.109 45 Ph Ph PhOC 1, HN MeCN NC Ph O + ClO74133 134 NH2 2-Benzopyrylium salt 135 undergoes similar recyclisation on treatment with malononitrile in the presence of sodium tert- butoxide in tert-butyl alcohol. This gives 2-amino-1-(3,4-di- methoxybenzoyl)-4-methyl-6,7-dimethoxynaphthalene-3-carbo- nitrile 136 in 33% yield.110 COR MeO MeO R NH2 + 1, ButONa ButOH CN MeO MeO OClO74135 136 Me Me R=3,4-(MeO)2C6H3. Of other examples of recyclisation of six-membered oxygen- containing heterocycles with malononitrile, the formation of (2- amino-3-cyano-4H-1-benzopyran-4-yl)acetamide 138 from cou- marin 137 should be mentioned.111 CH2CONH2 CN 1, NH3 O O NH2 138 O 137 It has been reported 112 that 2-formyldimedone 139 reacts with malononitrile in the presence of piperidine in methanol or ethanol to give 2-amino-4-dicyanomethyl-7,7-dimethyl-5-oxo-5,6,7,8-tet- rahydrobenzopyran-3-carbonitrile 140 in 78% yield and 3-cyano- 7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-2(1H)-quinolone 141 in 20% yield.Me O 1, HN Me H CHO 139 O Me Me O HN O NH2 Me Me + CN CN O O CH(CN)2 141 140 A new method for the synthesis of comunds of the ben- zo[h]quinoline series 142 has been proposed.113 The method is based on the Michael addition of malononitrile to 2-arylidene-1- tetralones 143 in the presence of sodium methoxide in methanol.The reaction mechanism was confirmed by isolation of the reaction intermediate, 4H-naphtho[1,2-b]pyran 144. NC CN O C6H4R-4 O 1, MeONa C6H4R-4 MeOH 143 OR0 NH2 CN CN N O R0O7 C6H4R-4 C6H4R-4 144 142 (73% ± 92%) R=H, Me, Cl, OMe, NO2; R 0 =Me, Et.46 The condensation of pyrazolinone 145 with malononitrile in the presence of ammonium acetate and methyl ethyl ketone on refluxing in ethanol for 3 h gives rise to substituted nicotinonitrile 146.114,115 Me CHO N O OH NC6H4NO2-4 145 MeN O NC6H4NO2-4 MeN O NC6H4NO2-4 The reaction of 4H-pyrans 147, incorporating a dicyano- methylene fragment, with amines is accompanied by recyclisation and results in the formation of 4-dicyanomethylene-1,4-dihydro- pyridines 148.116 ± 118 R NC NC RNH2 O NC NC R 147 R=Alk, Ar.However, the reactions of 4-dicyanomethylene-2-phenyl-4H- benzo[b]pyran 149a and the corresponding thiopyran 149b with malononitrile in methanol in the presence of KOH gives 5-ami- no-4-cyano-2-phenylbenzo[b]pyrano[4,3,2-de][1,6]naphthiridine 150a or the corresponding thiopyranonaphthiridine 150b.119 CN NC 1, KOH MeOH Ph X 149a,b X=O (a), S (b). The benzopyran 149a reacts with primary amines under mild conditions giving rise to 4-amino-5-R-imino-2-phenyl-4H-[1]ben- zopyrano[3,4-c]pyridines 151.120 Ph RNH2 149a O 151 R=Ph, Bn, PhNH. In order to synthesise analogues of the antitumour antibiotic streptonigrin, recyclisation of 4-dicyanomethylene-2-(2-qui- nolyl)-4H-[1]benzopyran 152 in pyridine in the presence of NH4OH has been studied.This reaction gave 4-amino-5-imino- 2-(2-quinolyl)-4H-[1]benzopyrano[3,4-c]pyridine 153 in 91% yield.121 1 CN MeEtCO O NH Me Me N NH2 CN OH 146 (60%) RNR 148 R PhN CN X NH2 N 150a,b N NH2 NR NC R=Recyclisation of 4-dicyanomethylene-2-(2-hydrophenyl)-4H- [1,3]benzoxazine 154 induced by various nucleophiles follows a similar pathway. Thus refluxing of the benzoxazine 154 in 2-methoxyethanol in the presence of ammonium acetate affords 2-(2-hydroxyphenyl)-4,5-diimino-3,4-dihydro-5H-[1]benzopyra- no[4,3-d]pyrimidine 155a in 91% yield.122 The thiazine 155b was prepared by treatment of the benzoxazine 154 with hydrogen sulfide in the presence of triethylamine, and the 1,3-oxazine 155c was synthesised by treatment of the compound 154 with hydro- chloric acid in 2-methoxyethanol.It was noted that adducts 156a ± c are formed as intermediates in this reaction; in the case of the thiazine 155b and oxazine 155c, the Dimroth rearrangement occurs under the reaction conditions, yielding 2-(2-hydroxy- phenyl)-5-imino-4-thio-3,4-dihydro-5H-[1]benzopyrano[4,3-d]p- y-rimidine 157 and 2-(2-hydroxyphenyl)-4,5-dioxo-3,4-dihydro- 5H-[1]benzopyranopyrimidine 158.122 NC 155b 155c X=NH (a), S (b), O (c).When isatic anhydride [2H-3,1-benzoxazine-2,4(1H)-dione] and its substituted derivatives 159 react with malononitrile in DMF in the presence of triethylamine and then the reaction mixture is hydrolysed with 48% HBr or 6N KOH, they are converted into 2-amino-4-hydroxyquinolines 160.123, 124 Com- pounds 161 and 162 were identified as reaction intermediates. R R O NH4OH, Py O CN 153 152 . NO C6H4OH-2H2X N HONC CN 154 C6H4OH-2 N X O 155a ± c NHN NHC6H4OH-2 NH S O 157 (79%) NH N C6H4OH-2 NH O O 158 (45%) O O R O 1, Et3N DMF O HN 159 V P Litvinov RNNH2 NH HN C6H4OH-2 X CN 156a ± c OH CN+ NH2 N 161Recyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives OH O R R CCH(CN)2 + NH2 NH2 N 160 (73% ± 86%) 162 R=H, Cl, Me, OMe.Recyclisation of pyrimidines involving malononitrile has been studied comprehensively.19, 125 ± 136 For the reaction of 1,4,6- trimethylpyrimidinium iodide 163, it was found that first the 4(6)-position of the pyrimidine nucleus in the compound 163 is attacked by the malononitrile anion, which gives adduct 164. Then the pyrimidine ring in the compound 164 is cleaved at the N(3) ± C(4) bond. Due to the presence of both nucleophilic [the N(1) atom] and electrophilic [the nitrile group carbon atom] reaction sites, the intermediates 165 and 166 thus formed cyclise to give pyridine 167.The latter is stabilised by being converted into aminopyridine 168 upon abstraction of an aminomethylene frag- ment as methylamine and formic acid.125 Me Me Me N N N 1, Et3N Me I7 Me 7H+ NC N 7N Me N + (CN)2HC Me CN Me 165 Me 163 164 Me Me7 NCH NMe H+ NCH NMe H2O C N Me N7 Me 167 166 CN CN MeN +MeNH2+HCO2H Me NH2 CN 168 Recyclisation of 2,3-disubstituted 4(1H)-pyrimidinethiones 169 on treatment with malononitrile in ethanol in the presence of sodium ethoxide affords pyridinethiones 170 in 78% ±93% yields.128 S S S NC NC 1, EtONa R2N C 7 EtOH N HN N N R1 N 169 NR2 R1 R1 NR2 S NC N H2N NR2 R1 170 R1=Ph: R2=Ph, 3-MeC6H4, 4-MeC6H4; R1=R2=4-MeC6H4.Recyclisation of 2(1H)-pyrimidinediones 129 and fused pyri- midines, such as quinazolines,132 1H-pyrazolo[3,4-d]pyrimi- dines 131 and their 3-oxides 130 occurs in a similar way. The scheme for the recyclisation of pyrimidinediones can be represented in relation to the interaction of 5-cyano-1,3-dimethyluracil 171 with malononitrile.134, 135 47 O O CN Me CN Me N N 1, EtONa H EtOH HCN N O O N C CN Me 171 Me H O O CN Me CN Me N N CN C O N 7N O N N Me Me . . C H NH O CN Me N N N O NH2 Me Recyclisation of 1-thia-2a,5a-diazaacenaphthene system 172 on treatment with malononitrile in ethanol in the presence of sodium ethoxide giving fused tetracyclic heterocyclic compound 173 in 88% yield has been described.136 +NH2Cl7 NH2 S S N N CH(CN)2 1, EtONa EtOH, 25 8C N N CN CN 172 O Me O Me NH NH S S N N N NH2 NH2CN N N CN CN 173 Me O Me O The recyclisation of 1-phenylphthalazine 3-oxide 174 during its reaction with malononitrile in methanol in the presence of sodium methoxide is accompanied by the loss of two nitrogen atoms and gives 3-phenylindene-2-carbonitrile 175.137 Ph Ph N 1, MeONa CN MeOH N O 175 174 The recyclisation of 2,3-diphenyl-5,6-dihydropyrazine 176 occurring on refluxing with malononitrile in ethanol over a period of 1 h follows a peculiar pathway and affords 2,6-diamino-4,10- diphenyl-1,7-diazatricyclo[5.2.1.04,10]deca-2,5-diene-3,5-dicarbo- nitrile 177 in 70% yield.138 7 (CN)2C (CN)2HC N Ph HN HN 1, EtOH Ph Ph Ph Ph Ph N N + H N 176 Ph Ph CN NC NH 1 HN N Ph NC Ph HN NH48 Ph CN NC N N NH2 H2N Ph 177 Recyclisation of 1,3,5-oxadiazinium salts 178 with participa- tion of malononitrile carried out in acetonitrile in the presence of triethylamine has been reported.2-Amino-6-aryl-4-carbamido- pyrimidines 179 were obtained in this way in 65%± 83% yields.139 NR2R3 NR2R3 1, Et3N N N NHCONR2R3 N + MeCN CN X7 NR2R3 R1 R1 O 178 CN NR2R3 N N NHCONR2R3 R1 CN 179 R1=Ph: R2=Me, R3=Me; R2,R3=(CH2)5, (CH2)2O(CH2)2. When reacting with malononitrile, 1,3,5-triazine undergoes recyclisation, similar to the transformation of pyrimidines into pyridines.This gives 4-aminopyrimidine-5-carbonitrile in 80% yield.140, 141 Recyclisation of 4H-1,2,4,6-thiatriazine 1,1-dioxide 180 yielding 3-amino-4-cyano-1,2,6-thiadiazine 1,1-dioxide 181 should be classified as the same type of reaction.142 HN NH CH(CN)2 (NC)2HC 1 HN HN NH NH S S O O O O 180 CN CN HN CH(CN)2 NC N HN C. . NH2 NH HN S S O O O O CN NH2 HN N S O O 181 3-Cyanopyridin-2(1H)-ones, -thiones, -selenones and their derivatives represent an important class of heterocyclic com- pounds because of the diversity of their chemical transformations and the possible practical applications.36, 76, 143 ± 154 These bifunc- tional compounds, which contain the nitrile and the oxo ± hydroxy, thione ± thiol or selenone ± selenol functional groups in the vicinal positions, proved to be promising starting compounds in the preparation of annelated heterocyclic systems difficult to obtain by other methods.143, 144 The strategy of the synthesis of 3-cyano-2-pyridinones, -thiones and -selenones and their hydro- genated analogues is based, first of all, on cyclisation of function- ally substituted carbonyl compounds or their derivatives with malononitrile or other derivatives of cyanoacetic acid.155 ± 164 During these studies it was found that thio(seleno)pyrans 182a,b are formed in the reactions of arylidenemalononitriles 183 with cyanothio(or seleno)acetamides 184a,b, or in a one-step procedure involving aromatic aldehydes, malononitrile, and the amides 184a,b, or in the reactions of arylidenecyanothio(or seleno)- acetamides 185a,b with malononitrile.The compounds 182a,b readily recyclise to give the corresponding pyridinethiones (or selenones) 186a,b.143, 144, 155, 157, 159, 161, 164 ± 179 NC X + NCCH2CNH2 Ar NC 183 184a,b ArCHO+184a,b NC Ar H2NCX 185a,b Ar CN NC C 7X NH2 N Ar CN NC X H2N HN 186a,b X=S (a), Se (b). According to the results of physicochemical studies, including X-ray diffraction analysis, the thio(or seleno)pyran ring in the compounds 182a,b occurs in the flattened boat conformation in which the aryl substituent at the 4-position is equato- rial.159, 168, 180 ± 183 The steric overcrowding of the thio(or seleno)- pyran molecules 182a,b with bulky electron-withdrawing substituents hampers the bond inversion in the ring and inversion of the substituents and thus makes impossible the conformational transitions in the heterocycle at higher temperatures.Therefore, on heating, ring cleavage at the weakest bond occurs (it is denoted by a dashed line in the scheme) and the compounds 182a,b are then converted into pyridinethiones(or selenones) 186a,b. In some studies,165, 184 ± 186 faulty data on the structures of the thiopyrans 182a and the pyridinethiones 186a are presented. The structure of the thiopyrans 182a (Ar = 4-ClC6H4, 4-MeOC6H4) was attrib- uted to the corresponding pyridinethiones 186a.165, 168 The struc- tures of 5-acetyl-2-amino-4-(4-methoxyphenyl)-6-methyl-4H- thiopyran-3-carbonitrile and 2,4-diamino-5-cyano-3-(2-furyl)- methylene-3,6-dihydropyridine-6-thione reported in the litera- ture 185, 186 are also erroneous.In addition, it has been found that the thiopyrans 182a recyclise on treatment with dimedone 187 to give 2-amino-4H-pyran-3-carbonitriles 188, whereas on treatment with ketones, 182a are converted into pyridinethiones 189.187 O 182a + O 187 R1 182a+R1CH2COR2 R2 An original pathway to substituted pyridinethiones 190 has been proposed.188 The reaction of b-enaminothioamides 191 with malononitrile under kinetically controlled conditions gives sub- stituted thiopyrans 192; on heating with a base under thermody- namically controlled conditions, these products are converted into pyridinethiones 190, their yields being more than 80%.V P Litvinov Ar CN NC 1 C 7 X N H N 1 H Ar CN NC D X NH2 H2N 182a,b O Ar CN NH2 O 188 Ar CN S HN 18949 Recyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives Ph Ph NC NaOH 1 N ArHNC EtOH S NAr H2N O S 192 191 Ph NC NHAr S HN 190 Ar=Ph, 4-MeC6H4, 4-ClC6H4, 4-BrC6H4, 4-MeOC6H4. Yet another convenient route to substituted 3-cyanopyridine- 2(1H)-thiones is recyclisation of enamino nitriles of the 1,3- dithiacyclohexene series.191 ± 202 In particular, it was found that 2,2-dialkyl-6-aryl-1,3-dithiacyclohex-4-enes are converted into 3-cyanopyridine-2(1H)-thiones 189 in high yields.25, 144,193, 194 This reaction is formally accompanied by elimination of a hydro- gen sulfide molecule and two hydrogen atoms, the subsequent transformations being determined by the structure of the initial substrate.The reaction conditions also have a substantial influ- ence on its course. For example, recyclisation of 1,3-dithiacyclo- hex-4-ene 199 carried out in the presence of an organic base in methanol at 20 ± 25 8C yields pyridinethione 200, whereas heating of the compound 199 in DMF at 150 ± 160 8C gives a mixture of the pyridinethiones 200 and 201. Ar CN Me MeOH NH2 20 ± 25 8C Recyclisation of 6-amino-3,4-tetramethylene-2-thiothio- pyran-5-carbonitrile 193 involving organic bases affords substi- 3-cyano-4,5-tetramethylene-1,2-dihydropyridine-2(1H)- S Me CN HN S R1=R2=Me tuted thiones 194.189 H2N S R1H2C 200 Ar S Ar S NH R2 CN S NC X N NC 199 DMF +HN X +200 7H2S 150 ± 160 8C S Et NH194 193 201 X=O, CH2.The ylidene-derivatives of 6-amino-2H-thiopyran-5-carbon- itrile 195, prepared from thiopyrylium salts, are converted into 2,6-dicyano-3-sulfanylanilines 196; this reaction is similar to the reactions of pyrylium salts with nucleophiles.187 R3 R3 CN R2 CN R2 MeONa MeOH R1OC SHCN S NH2 H NC COR1 CN 195 To elucidate the recyclisation mechanism, 4-amino-6-phenyl- 2-cyclohexanespiro-1,3-dithiacyclohex-4-ene-5-carbonitrile 199 [Ar = Ph, R1,R2 = (CH2)4] was studied by X-ray diffraction analysis.198 The results led to the conclusion that the molecules of 1,3-dithiacyclohex-4-enes 199 contain a conformationally rigid intramolecular system. Therefore, energy supplied from the out- side causes rupture of the weakest bonds, S(1) ± C(6) and S(3) ± C(2), (shown by a dashed line in the scheme), which results in the formation of cyclohexanethione or acyclic thioketones 202 and arylidenecyanothioacetamides 203 as intermediates.The com- pounds 202 and 203 are finally converted into 3-cyanopyridine- 2(1H)-thiones 189.25, 144, 194, 198 R3 R3 NH2 CN R2 CN R2 CN NC R1H2C S 7MeOCOR1 HS NH2 R1H2C HS Ar NH COR1 Ar NC R2 S +H2NSC203 S 199 R2 202 CN 196 R1=OMe, NH2: R2=Me, R3=Et; R2,R3=(CH2)4. Ar Ar CN R1 CN R1 7H2S CSNH2 In turn, piperidone 197, containing a cyanothioacetamide fragment, recyclises on refluxing in ethanol in the presence of a catalytic amount of piperidine to give 2,7-naphthiridine 198.190 S R2 S R2 HN O Ar CN Me HN CN R1 EtOH CSNH2 Me N S R2 HN 197 Me Me 189 Me CN Me MeN N CN Me EtO2C CSNH2 EtO2C Me CSNH2 CN CN S Me S Me 7H2 NH MeN MeN NH MeO MeO 198 (74%) The mechanism of recyclisation of 4H-thiopyrans and 1,3- dithiacyclohex-4-enes 199 was confirmed by studying their cross- recyclisation with various CH acids, a-methylene ketones, 1,3- dicarbonyl compounds and their enamines, ethyl cyanoacetate and malononitrile.25, 143, 144, 181 ± 183 Under thermodynamically controlled conditions, cycloelimination of heterocyclic com- pounds 182 and 199 occurs, yielding arylidenecyanothioacet- amides 203 and either malononitrile or thioketones, respectively.The subsequent competing transformations of the amides 203 involving malononitrile or carbonyl compounds give rise to substituted pyridinethiones 204 or 186a.50 Ar CN NC 7CH2(CN)2 NH2 H2N XCH2COY D [203] S 182a NH2 [or CH2(CN)2] CN S CH2R1 R1H2C 7S Ar R2 R2 S 199 Ar Ar NC CN CN X or S S H2N Y NH NH 204 186a X=Alk, OAlk; Y=Alk. To elucidate the mechanism and stereochemistry of trans- formations of the heterocyclic compounds 182a and 199, their reactions with pyridinium ylides have been studied.144, 156, 181, 182 It was found that in this case, too, arylidenecyanothioacetamides 203 are formed as intermediates; they react stereoselectively with pyridinium ylides to give 3,4-trans-1,2,3,4-tetrahydropyridine-2- thiolates 205.The latter are converted into pyridinethiones 206 on heating with ammonium acetate in acetic acid. + Ar H N 7 AcONH4 CN 203+ +NCHCOR AcOH R HO S7 R HN 205 Ar CN S R NH206 The results obtained demonstrated that the stereochemistry and the electronic structures of heterocyclic compounds 182a and 199 have similar features, namely, (1) both molecules contain a planar enaminonitrile fragment with a well-developed system of p,p-conjugation; (2) they are partially hydrogenated; (3) they contain a nonplanar ring sterically overcrowded with alkyl and aryl substituents; (4) they contain one or several electron-with- drawing groups as substituents. Due to these features, when the enthalpy increases, the compounds 182a and 199 cannot decrease their energy upon conformational transitions; instead, they undergo cycloelimination involving the weakest bonds.The reactions of arylidenecyanothioacetamides 203 with dimedone afford substituted pyrans 207, which recyclise in the presence of bases to give intermediates 208 and then quinoline- thiolates 209.203 ± 206 Ar O O CSNH2 B : 25 8C 203+ O NH2 O 207 187 Ar O Ar O CN CN D BH+ S7 CSNH2 O7BH+ N 209 208 V P Litvinov V. Conclusion The data on recyclisation of carbo- and heterocyclic compounds with participation of malononitrile and its derivatives considered here clearly demonstrate the high synthetic potential of these reactions and good prospects for using them in the syntheses of various compounds, including products that are difficult to obtain by other methods, which possess a broad spectrum of useful properties.The review was written with the financial support of the Russian Foundation for Basic Research (Project No. 96-03- 32012a). References 1. O P Shvaika, V N Artemov Usp. Khim. 41 1788 (1972) [Russ. Chem. Rev. 41 883 (1972)] 2. H C van der Plas Ring Transformation of Heterocycles Vol. 1,2 (London, New York: Academic Press, 1973) 3. A J Boulton, in Lectures in Heterocyclic Chemistry Vol. 2 (Eds R N Castle, L B Townsend) (Orem-Utah: Heterocorporation, 1974) p. S-45 4. O P Shvaika, Doctoral Thesis in Chemical Sciences, Kiev State University, Kiev, 1976 5.Ya P Stradyn' Khim. Geterotsikl. Soedin. 1570 (1979) a 6. R S Sagittulin, Doctoral Thesis in Chemical Sciences, Moscow State University, Moscow, 1979 7. A Padwa, in Rearrangements in Ground and Excited States Vol. 3 (Ed. P de Mayo) (New York: Academic Press, 1980) p. 501 8. J Becher Synthesis 589 (1980) 9. C A Ramsden Adv. Heterocycl. Chem. 26 1 (1980) 10. M Riccia,N Vivona,D Spinelli Adv. Heterocycl. Chem. 29 141 (1981) 11. A N Kost, S P Gromov, R S Sagittulin Tetrahedron 37 3423 (1981) 12. A T Balaban (Ed.) Pyrylium Salts. Synthesis, Reactions and Physical Properties (New York: Academic Press, 1982) 13. C L'Abbe J. Heterocycl. Chem. 21 627 (1984) 14.V N Charushin, O N Chupakhin Usp. Khim. 53 1648 (1984) [Russ. Chem. Rev. 53 956 (1984)] 15. A R Katritzky, CW Ress (Eds) Comprehensive Heterocyclic Chemistry Vol. 1 ± 8 (Oxford: Pergamon Press, 1984) 16. D L Boger Chem. Rev. 86 781 (1986) 17. A Kato, T Nishio, C Kashina Heterocycles 26 2223 (1987) 18. A T Balaban, in Proceedings of the 6th IUPAC Symposium on Organic Chemistry (Abstracts of Reports), Moscow, 1986 p. 263 19. W Schroth, in Chemistry of Heterocyclic Compounds (Eds R N J Kovac, P Zalupsky) (Amsterdam; Elsevier, 1988) p. 115 20. A R Katritzky, N Dennis Chem. Rev. 89 827 (1989) 21. N V Alekseeva, L N Yakhontov Usp. Khim. 59 888 (1990) [Russ. Chem. Rev. 59 514 (1990)] 22. V G Andrianov, A V Eremeev Khim. Geterotsikl. Soedin.1443 (1990) a 23. V I Terenin, E V Babaev,M A Yurovskaya, Yu G Bundel' Khim. Geterotsikl. Soedin. 792 (1992) a 24. E V Babaev, N S Zefirov Khim. Geterotsikl. Soedin. 808 (1992) a 25. Yu A Sharanin, V K Promonenkov, V P Litvinov, in Organicheskaya Khimiya (Itogi Nauki i Tekhniki) [Organic Chemistry (Advances in Sciences and Engineering Series)] (Moscow: Izd. VIN- ITI, 1991) Vol. 20, Parts 1, 2 26. W Norden, V Sander, P Weyerstahl Chem. Ber. 116 3097 (1983) 27. W F Berkowitz, S C Grenetz J. Org. Chem. 41 10 (1976) 28. O V Kayukova, Candidate Thesis in Chemical Sciences, Moscow State University, Moscow, 1977 29. O V Yashkanova, O E Nasakin, Ya G Urman, V N Khrustalev, V N Nesterov,M Yu Antipin, P M Lukin Zh. Org. Khim. 33 533 (1997) b 30.O V Yashkanova, O E Nasakin, Ya G Urman, V N Khrustalev, V N Nesterov,M Yu Antipin, P M Lukin, E V Vershinin Zh. Org. Khim. 33 542 (1997) b 31. O V Yashkanova, P M Lukin, O E Nasakin, Ya G Urman, V N Khrustalev, V N Nesterov,M Yu Antipin Zh. Org. Khim. 33 943 (1997) bRecyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives 32. S Spaka, P M Lukin,O E Nasakin, V N Khrustalev,V N Nesterov, M Yu Antipin, O V Pul'kherovskaya Zh. Org. Khim. 33 905 (1997) b 33. M Takahachi, T Orihara, T Sasaki, T Yamatera Heterocycles 24 2857 (1986) 34. T Eicher, W Freihoff Synthesis 908 (1986) 35. T Eicher, U Stapperfenne Synthesis 619 (1987) 36. F S Babichev, Yu A Sharanin, V P Litvinov, V K Promonenkov, Yu M Volovenko Vnutrimolekulyarnoe Vzaimodeistvie Nitril'noi i CH-, OH- i SH-grupp (Intramolecular Interaction of Nitrile and CH, OH and SH Groups) (Kiev: Naukova Dumka, 1985) 37.A V Fokin, A F Kolomiets Khimiya Tiiranov (The Chemistry of Thiiranes) (Moscow: Nauka, 1978) 38. A V Fokin, M A Allakhverdiev, A F Kolomiets Usp. Khim. 59 705 (1990) [Russ. Chem. Rev. 59 405 (1990)] 39. F S Babichev, Yu A Sharanin, V K Promonenkov, V P Litvinov, Yu M Volovenko Vnutrimolekulyarnoe Vzaimodeistvie Nitril'noi i Aminogrupp (Intramolecular Interaction of Nitrile and Amino Groups) (Kiev: Naukova Dumka, 1987) 40. E Campaigne, R L Ellis,M Bradford J. Heterocycl. Chem. 6 159 (1969) 41. T Matsuda, K Yamagata, Y Tomioka, M Yamazaki Chem. Pharm. Bull. 33 937 (1985) 42.H Wamhoff, H-A Thiemig Chem. Ber. 118 4473 (1985) 43. I F Sokovishina, V V Perekalin, O M Lerner, L M Andreeva Zh. Org. Khim. 1 636 (1965) b 44. I F Sokovishina, L N Zorina, in XXVI Gertsenovskie Chteniya (The XXVIth Gertsen Lectures) (Leningrad: Khimiya, 1973) Vol. 2, p. 105 45. I F Sokovishina, V V Perekalin Zh. Org. Khim. 11 52 (1975) b 46. S I Selivanov, Yu A Sharanin, R A Bogatkin, B A Ershov Zh. Org. Khim. 17 666 (1981) b 47. B A Ershov, L A Kaunova, Yu A Kleiman, T V Markina Zh. Org. Khim. 4 1764 (1968) b 48. Z Rappoport (Ed.) The Chemistry of the Cyanogroup (New York: Interscience, 1970) 49. J L Guinamant, A Robert Tetrahedron 42 1169 (1986) 50. K Yamagata, Y Tomioka, M Yamazaki, T Matsuda, K Noda Chem. Pharm. Bull. 30 4396 (1982) 51.Y Taguchi, Y Suhara Bull. Chem. Soc. Jpn. 59 2321 (1986) 52. Y Taguchi, Y Suhara J. Nat. Chem. Lab. Ind. 82 277 (1987) 53. M Sonoda, N Kuriyama, Y Tomioka, M Yamazaki Chem. Pharm. Bull. 30 2357 (1982) 54. B Buchholz, H Stamm Chem. Ber. 120 1239 (1987) 55. T Kato, Y Kubota,M Tanaka Hetrocycles 9 841 (1978) 56. T Kato, N Katagiri, R Sato Chem. Pharm. Bull. 29 2361 (1981) 57. O E Nasakin, P M Lukin, V P Sheverdov, S N Krasnokutskii, S V Medvedev, P A Sharbatyan, V A Tafeenko Khim. Geterotsikl. Soedin. 846 (1990) a 58. O E Nasakin, V P Sheverdov, P M Lukin, S N Krasnokutskii, P A Sharbatyan, S V Medvedev, A B Zolotoi, V A Tafeenko Khim. Geterotsikl. Soedin. 996 (1990) a 59. G J Ashwell, M R Bryce, S R Davies,M Hasan J. Org.Chem. 53 4585 (1988) 60. T Nozoe Pure Appl. Chem. 28 239 (1971) 61. V B Mochalin, Yu N Porshnev Usp. Khim. 46 1002 (1977) [Russ. Chem. Rev. 46 (1977)] 62. T Nozoe, K Takase, T Nakazawa, S Fukuda Tetrahedron 27 3357 (1971) 63. K Takase, T Nakazawa, T Nozoe Heterocycles 15 839 (1981) 64. O E Nasakin, A N Lyshchikov, P M Lukin, V A Tafeenko, A Kh Bulai, S V Medvedev Khim. Geterotsikl. Soedin. 1325 (1992) a 65. O E Nasakin, A N Lyshchikov, P M Lukin, A Kh Bulai, V A Tafeenko, P A Sharbatyan Khim. Geterotsikl. Soedin. 1502 (1991) a 66. O E Nasakin, A N Lyshchikov, P M Lukin, V A Tafeenko Khim. Geterotsikl. Soedin. 1472 (1992) a 67. P B Ghosh, B Ternai J. Org. Chem. 37 1047 (1972) 68. T Nishiwaki Synthesis 20 (1975) 69. J A Ciller, N Martin, C Leoane, J L Soto J.Chem. Soc., Perkin Trans. 1 2581 (1985) 70. A S Prasad, J S Sandhu, J N Baruah Heterocycles 20 787 (1983) 71. D Konwar, R C Borush, J S Sandhu Heterocycles 23 2257 (1985) 72. E C Taylor, J Bartulin Tetrahedron Lett. 2337 (1967) 73. K Gewald, U Hain, P Hartung Monatsh. Chem. 112 1393 (1981) 74. B Zaleska J. Prakt. Chem. 329 787 (1987) 51 75. P Molina, A Arques, I Cartagena, P M Fresneda Synth. Commun. 17 1929 (1987) 76. P Molina, A Arques, I Cartagena, M V Valcarcel J. Heterocycl. Chem. 22 1189 (1985) 77. V P Litvinov, Yu A Sharanin, F S Babichev Sulfur Rep. 6 97 (1986) 78. H Hartmann Z. Chem. 11 421 (1971) 79. H Hartmann, H Schafer,K Gewald J. Prakt. Chem. 315 497 (1973) 80. P Czerney, H Hartmann J. Prakt.Chem. 325 551 (1983) 81. K Hirai, T Ishida Chem. Pharm. Bull. 20 2384 (1972) 82. K Hirai, T Ishida Chem. Pharm. Bull. 19 2194 (1971) 83. J-M Catel, Y Mollier Bull. Soc. Chim. Fr. 343 (1982) 84. R L N Harris, H G McFadden Aust. J. Chem. 37 2479 (1984) 85. K Yonemoto, I Shibuya, K Honda Bull. Chem. Soc. Jpn. 62 1086 (1989) 86. I Shubuya Bull. Chem. Soc. Jpn. 57 605 (1984) 87. D Briel, S Leistner, G Wagner Synthesis 535 (1985) 88. D Martin, F Tittelbach J. Chem. Soc., Perkin Trans. 1 1007 (1985) 89. A Chimirri, S Grasso, G Romeo,M Zappala Heterocycles 27 1975 (1988) 90. K Ley, F Seng, U Eholzer, R Nast, R Schubart Angew. Chem. 81 569 (1969) 91. F Seng, K Ley Angew. Chem. 84 1061 (1972) 92. H N Borah, R S Boruah, J S Sandhu Heterocycles 22 2323 (1985) 93.H-J Forster, H-J Niclas, N G Lukyanenko Z. Chem. 25 102 (1985) 94. Yu T Abramenko, Yu A Baskakov, Yu A Sharanin, A F Vasil'ev, E B Nazarova, N A Kiseleva, O N Vlasov Zh. Vses. Khim. O-va im. D I Mendeleeva 24 408 (1979) c 95. Yu T Abramenko, Yu A Baskakov, Yu A Sharanin, N A Kiseleva, O N Vlasov, Yu G Putsykin, V V Negrebetskii Zh. Vses. Khim. O-va im. D I Mendeleeva 24 409 (1979) c 96. Yu A Sharanin, Yu A Baskakov, Yu T Abramenko, Yu G Putsykin, A F Vasil'ev, E B Nazarova Zh. Org. Khim. 16 2192 (1980) b 97. Yu A Sharanin, Yu A Baskakov, Yu T Abramenko, Yu G Putsykin, E B Nazarova, A F Vasil'ev Zh. Org. Khim. 20 1508 (1984) b 98. Yu T Abramenko, A V Ivashchenko, K A Nogaeva, N A Andronova, E B Putsykina Zh. Org.Khim. 22 264 (1986) b 99. Yu T Abramenko, A V Ivashchenko, K A Nogaeva, Yu A Sharanin Khim. Geterotsikl. Soedin. 621 (1986) a 100. Yu A Sharanin, G E Khoroshilov, O M Nefedov, V P Litvinov, A M Shestopalov Zh. Org. Khim. 25 1315 (1989) b 101. A J Fatiadi Synthesis 165 (1978) 102. E Yu Gudrinietse, E L Palitis, V P Barkan Izv. Akad. Nauk Latv. SSR 614 (1983) 103. K Dimroth, G Neubauer Angew. Chem. 69 720 (1957) 104. K Dimroth, G Neubauer Chem. Ber. 92 2046 (1959) 105. K Dimroth Angew. Chem. 72 331 (1960) 106. K Dimroth, K H Wolf Newer Methods of Preparative Organic Chemistry Vol. 3, Suppl., Part 3 (New York: Academic Press, 1984) 107. J A Van Allan, G A Reynolds, C C Petropoulos J. Heterocycl. Chem. 9 783 (1972) 108. G A Reynolds, J A VanAllan J.Heterocycl. Chem. 8 301 (1971) 109. J A VanAllan, G A Reynolds J. Heterocycl. Chem. 14 119 (1977) 110. S V Verin, D E Tosunyan, E V Kuznetsov, Yu A Zhdanov Khim. Geterotsikl. Soedin. 315 (1990) a 111. H Junek, H Sterk Monatsh. Chem. 98 144 (1967) 112. E Yu Gudrinietse, T F Pakhurova, E E Liepin'sh Zh. Org. Khim. 18 2361 (1982) b 113. H-H Otto, O Rinus, H Schmelz Monatsh. Chem. 110 115 (1979) 114. M A Metwally, A A Fadda, H M Hassan, E Afsah Org. Prep. Proceed. Int. 17 198 (1985) 115. S Markhalin, D Ilavsky, J Kovac,M Bruncko Collect. Czech. Chem. Commun. 55 718 (1990) 116. H Kato, T Ogawa,M Ohta Bull. Chem. Soc. Jpn. 33 1468 (1960) 117. J A VanAllan, G A Reynolds, C C Petropoulos, D P Maier J. Heterocycl. Chem. 7 495 (1970) 118. J A VanAllan, G A Reynolds J.Heterocycl. Chem. 8 367 (1971) 119. J A VanAllan, C C Petropoulos, G A Reynolds, D P Maier J. Heterocycl. Chem. 7 1363 (1970) 120. G A Reynolds, J A VanAllan, C C Petropoulos J. Heterocycl. Chem. 7 1061 (1970) 121. M Cushman, J Mathew J. Org. Chem. 46 4921 (1981)52 122. D Briel, S Leistner, G Wagner Synthesis 147 (1986) 123. A M van Leusen, J Wildeman Synthesis 500 (1977) 124. G M Coppola Synthesis 505 (1980) 125. R S Sagitullin, A N Kost Zh. Org. Khim. 16 658 (1980) b 126. T V Stupnikova, Kh Ya Lopatinskaya Khim. Geterotsikl. Soedin. 1566 (1980) a 127. V N Charushin, H C van der Plas Recl. Trav. Chim. Pays Bas. 102 373 (1983) 128. A Katoh, Y Omote, C Kashima Heterocycles 22 763 (1984) 129. A Katoh, Y Omote, C Kashima Chem.Pharm. Bull. 32 2942 (1984) 130. T Higashino, E Hayashi Chem. Pharm. Bull. 21 3643 (1973) 131. T Higashino,Y Iwai, E Hayashi Chem. Pharm. Bull. 24 3120 (1976) 132. T Higashino, K Suzuki, E Hayashi Chem. Pharm. Bull. 26 3485 (1978) 133. T Higashino, K Suzuki, E Hayashi Chem. Pharm. Bull. 26 3242 (1978) 134. T-L Su, K A Watanabe J. Heterocycl. Chem. 19 1261 (1982) 135. T-L Su, K A Watanabe J. Heterocycl. Chem. 21 1543 (1984) 136. I Bitter, G Toth, B Pete, I Hermecz, K Simon, Z Meszaros Heterocycles 24 69 (1986) 137. E Oishi, A Yamada, S Ota, T Higashino Heterocycles 24 238 (1986) 138. P Beak, R A Brown, J Yamamoto, C C Chiang, I C Paul J. Org. Chem. 41 3389 (1976) 139. H Hartmann, J Liebscher, P Czerney Tetrahedron 41 5371 (1985) 140.H Neff, K-D Kohnert, A Schellenberger J. Prakt. Chem. 315 701 (1973) 141. K R Huffman, F C Schaefer, G A Peters J. Org. Chem. 27 551 (1962) 142. P Goya, C Ochoa, J A Paez, I Rozas,M Stud Heterocycles 22 471 (1984) 143. V P Litvinov, L A Rodinovskaya, Yu A Sharanin, A M Shestopalov, A Senning Sulfur Rep. 13 1 (1992) 144. V P Litvinov, V K Promonenkov, Yu A Sharanin, A M Shestopalov, in Organicheskaya Khimiya (Itogi Nauki i Tekh- niki) [Organic Chemistry (Advances in Sciences and Engineering Series)] (Moscow: Izd. VINITI, 1989) Vol. 17, p. 72 145. L A Rodinovskaya, V K Promonenkov, Yu A Sharanin, V P Litvinov,A M Shestopalov, in Organicheskaya Khimiya (Itogi Nauki i Tekhniki) [Organic Chemistry (Advances in Sciences and Engineering Series)] (Moscow: Izd.VINITI, 1989) Vol. 17, p. 3 146. F Brody, P R Rubi, in Pyridine and its Derivatives Vol. 14, Part 1 (Ed. E Klingsberg) (New York: Interscience, 1960) p. 99 147. H Meislich, in Pyridine and its Derivatives Vol. 14, Part 3 (Ed. E Klingsberg) (New York: Interscience, 1962) p. 509 148. H L Yale, in Pyridine and its Derivatives Vol. 14, Part 4 (Ed. E Klingsberg) (New York: Interscience, 1964) p. 345 149. H L Yale, in Pyridine and its Derivatives Vol. 14, Suppl., Part 4 (Ed. E Klingsberg) (New York: Interscience, 1975) p. 189 150. H Tiekelmann, in Pyridine and its Derivatives Vol. 14, Suppl., Part 3 (Ed. R A Abramovitch) (New York: Interscience, 1974) p. 597 151. J Becher, C E Stidsen Sulfur Rep.8 105 (1988) 152. P M Abdel-Galil, S M Sherif, M H Elnagdi Heterocycles 24 2023 (1986) 153. B Y Ried, A M Negm, S E Abdou, H A Daboun Heterocycles 26 205 (1987) 154. M H Mohamed, N S Ibrahim, M H Elnagdi Heterocycles 26 899 (1987) 155. Yu A Sharanin, Doctoral Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1988 156. A M Shestopalov, Doctoral Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1991 157. L A Rodinovskaya, Doctoral Thesis in Chemical Sciences, Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 1994 158. E E Apenova, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1986 159. V N Nesterov, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1988 V P Litvinov 160. G V Klokol, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1988 161.V D Dyachenko, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Academy of Sciences of the USSR, Moscow, 1990 162. O P Bogomolova, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 1992 163. N G Frolova, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 1997 164. S G Krivokolysko, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 1997 165.G E Elgemeie, S M Sherif, F A Abd-Elaai, M H Elnagdi Z. Naturforsch., B Chem. Sci. 41 781 (1986) 166. F M Galil,M M Sallam, S M Sherif, M H Elnagdi Liebigs Ann. Chem. 1639 (1986) 167. H Z Shams, Y M Elkholy, N S Ibrahim,M H Elnagdi J. Prakt. Chem. 330 817 (1988) 168. Yu A Sharanin, V D Dyachenko Zh. Obshch. Khim. 57 1662 (1987) d 169. Yu A Sharanin, V D Dyachenko, A V Turov, V P Litvinov Ukr. Khim. Zh. 54 615 (1988) 170. V D Dyachenko, V N Nesterov, Yu T Struchkov, Yu A Sharanin, V E Shklover Zh. Obshch. Khim. 59 881 (1989) d 171. Yu A Sharanin, V K Promonenkov, A M Shestopalov, V N Nesterov, S N Melenchuk, V E Shklover, Yu T Struchkov Zh.Org. Khim. 25 622 (1989) b 172. Yu A Sharanin, A M Shestopalov, V N Nesterov, S N Melenchuk, V K Promonenkov, V E Shklover, Yu T Struchkov, V P Litvinov Zh. Org. Khim. 25 1323 (1989) b 173. Yu A Sharanin, V D Dyachenko Ukr. Khim. Zh. 56 287 (1990) 174. V P Litvinov Phosphorus Sulfur Silicon Relat. Elem. 74 139 (1993) 175. L A Rodinovskaya, A M Shestopalov, V P Litvinov Dokl. Akad Nauk 339 214 (1994) e 176. V D Dyachenko, S G Krivokolysko, V P Litvinov Khim. Geterotsikl. Soedin. 1099 (1996) a 177. V D Dyachenko, S G Krivokolysko, V P Litvinov Zh. Org. Khim. 33 1084 (1997) b 178. V D Dyachenko, S G Krivokolysko, Yu A Sharanin, V P Litvinov Khim. Geterotsikl. Soedin. 909 (1997) a 179. V D Dyachenko, V P Litvinov Khim.Geterotsikl. Soedin. 996 (1997) a 180. V N Nesterov, V E Shklover, Yu T Struchkov, Yu A Sharanin, A M Shestopalov, V P Litvinov in Tez. Dokl. V Vsesoyuz. Sove- shchaniya po Organicheskoi Kristallokhimii, Chernogolovka, 1987 (Abstracts of Reports at the Vth All-Union Meeting on Organic Crystal Chemistry, Chernogolovka, 1987) p. 146 181. V K Promonenkov, S V Otochevannaya, V K Zav'yalova, V P Litvinov, Yu A Sharanin, in Khimiya i Tekhnologiya Piridinsoderzhashchikh Pestitsidov (Tez. Dokl. Vsesoyuz. Konf.), Chernogolovka, 1988 [The Chemistry and Technology of Pyridine-Containing Pesticides (Abstracts of Reports of the All- Union Conference), Chernogolovka, 1988] p. 102 182. Yu A Sharanin, A M Shestopalov, V K Promonenkov, V P Litvinov, in Khimiya i Tekhnologiya Piridinsoderzhashchikh Pestitsidov (Tez.Dokl. Vsesoyuz. Konf.), Chernogolovka, 1988 [The Chemistry and Technology of Pyridine-Containing Pesticides (Abstracts of Reports of the All-Union Conference), Chernogolovka, 1988] p. 112 183. Yu A Sharanin, V K Promonenkov, V P Litvinov, A M Shestopalov, in Khimiya i Tekhnologiya Piridinsoderzhashchikh Pestitsidov (Tez. Dokl. Vsesoyuz. Konf.), Chernogolovka, 1988 [The Chemistry and Technology of Pyridine-Containing Pesticides (Abstracts of Reports of the All-Union Conference), Chernogolovka, 1988] p. 116 184. G E Elgemeie, E A Hafez, G A Nawar,M H Elnagdi Heterocycles 22 2829 (1984) 185. A M El-Torgoman, S M El-Cousy, K Z El-Shahat Z. Naturforsch., B Chem. Sci. 42 107 (1987) 186.Yu A Sharanin, A M Shestopalov Zh. Org. Khim. 25 1331 (1989) b 187. K Gewald, H Schaefer Z. Chem. 21 183 (1981) 188. E Augustyn, K Bogdanowicz-Szwed Monatsh. Chem. 114 1189 (1983)Recyclisation of carbo- and heterocyclic compounds involving malononitrile and its derivatives 189. K Gewald,M Buchwalder,M Peukert J. Prakt. Chem. 315 679 (1973) 190. V A Artemov, A M Shestopalov, V P Litvinov Khim. Geterotsikl. Soedin. 512 (1996) a 191. Yu A Sharanin, A M Shestopalov, V K Promonenkov, L A Rodinovskaya Zh. Org. Khim. 20 1539 (1984) b 192. Yu A Sharanin, A M Shestopalov, V K Promonenkov Zh. Org. Khim. 20 2002 (1984) b 193. Yu A Sharanin, A M Shestopalov, V K Promonenkov Zh. Org. Khim. 20 2012 (1984) b 194. V P Litvinov, Yu A Sharanin, A M Shestopalov Sulfur Lett. 3 99 (1985) 195. Yu A Sharanin, V K Promonenkov, A M Shestopalov, Yu T Abramenko, in Novye Khimicheskie Sredstva Zashchity Rastenii (New Chemical Means for Plant Protection) (Moscow: NIITEKhIM, 1979) p. 4 196. Yu A Sharanin, V K Promonenkov, A M Shestopalov Zh. Org. Khim. 18 1782 (1982) b 197. Yu A Sharanin, V K Promonenkov, A M Shestopalov Zh. Org. Khim. 18 2003 (1982) b 198. Yu A Sharanin, V P Litvinov, A M Shestopalov, V N Nesterov, Yu T Struchkov, V E Shklover, V K Promonenkov, V Yu Mortikov Izv. Akad. Nauk SSSR, Ser. Khim. 1768 (1985) f 199. Yu A Sharanin, V K Promonenkov, V P Litvinov, A M Shestopalov, in Novoe v Khimii Azinov (Tez. Dokl.), Sverdlovsk, 1985 [New in the Chemistry of Azines (Abstracts of Reports), Sverdlovsk, 1985] p. 75 200. V K Promonenkov, Yu A Sharanin, V P Litvinov, A M Shestopalov, Yu T Struchkov, V E Shklover, V N Nesterov, in Khimiya i Tekhnologiya Geterokumulenov dlya Proizvodstva Khimicheskikh Sredstv Zashchity Rastenii (Tez. Dokl. Vsesoyuz. Soveshch.), Moscow, 1985 [The Chemistry and Technology of Heterocumulenes for Production of Chemical Means for Plant Protection (Abstracts of Reports of the All-Union Meeting), Mos- cow, 1985] p. 44 201. Yu A Sharanin, V K Promonenkov, A M Shestopalov, in Vsesoyuz. Soveshch. po Khimii i Tekhnologii Piridinovykh Osnovanii dlya Proizvodstva Khimicheskikh Sredstv Zashchity Rastenii (Tez. Dokl.), Moscow, 1983 [The All-Union Meeting on the Chemistry and Technology of Pyridine Bases for Production of Chemical Means for Plant Protection (Abstracts of Reports), Moscow, 1983] p. 40 202. A M Shestopalov, Yu A Sharanin, V P Litvinov, V K Promonenkov Zh. Obshch. Khim. 59 2395 (1989) d 203. V K Promonenkov, Yu A Sharanin, M P Goncharenko, A M Shestopalov, S N Melenchuk, in Khimiya i Tekhnologiya Geterokumulenov dlya Proizvodstva Khimicheskikh Sredstv Zashchity Rastenii (Tez. Dokl. Vsesoyuz. Soveshch.), Moscow, 1985 [The Chemistry and Technology of Heterocumulenes for Produc- tion of Chemical Means for Plant Protection (Abstracts of Reports of the All-Union Meeting), Moscow, 1985] p. 57 204. M P Goncharenko, V K Promonenkov, Yu A Sharanin, in Khimiya i Tekhnologiya Piridinsoderzhashchikh Pestitsidov (Tez. Dokl. Vsesoyuz. Konf.), Chernogolovka, 1988 [The Chemistry and Technology of Pyridine-Containing Pesticides (Abstracts of Reports of the All-Union Conference), Chernogolovka, 1988] p. 125 205. Yu A Sharanin,M P Goncharenko Zh. Org. Khim. 24 460 (1988) b 206. M P Goncharenko, Candidate Thesis in Chemical Sciences, Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 1993 a�Chem. Heterocycl. Compd. (Engl. Transl.) b�Russ. J. Org. Chem. (Engl. Transl.) c�Mendeleev Chem. J. (Engl. Transl.) d�Russ. J. Gen. Chem. (Engl. Transl.) e�Dokl. Chem. Technol., Dokl. Chem. (Engl. Transl.) f�Russ. Chem. Bull. (Engl.