摘要:

Me X Y N NH Ar + Ph3P CHR N ArNH R¢O O Me Y P(Ph)3 A Me CH N Y HN Ar C OR¢ O B –(Ph)3P X N N Y Me Ar –R¢OH a Y = COMe X = O Ar = Ph b Y = CO2Et X = O Ar = Ph c Y = CN X = NH Ar = C6H4Me–4 1 a Y = COMe Ar = Ph b Y = CO2Et Ar = Ph c Y = CN Ar = C6H4Me–4 3 a R = CO2Me b R = CO2Et c R = COPh 2 O H X NNHAr O O 4 O 6 O O 7 CHR N N O Ar O 5 + Ph3P CHR toluene –TPPO 2a,b NNHPh O CHR 8 R = CO2R¢ ArN NCl + – 9a 5a Y = COPh R = CO2R¢ a b c Ar = Ph Ar = C6H4Me-4 Ar = C6H4NO2-4 4,5 a b c Ar = CO2Me Ar = CO2Et Ar = COPh 2,7,8 ArN NCl + – 2a–c 236 J. CHEM. RESEARCH (S) 1997 J. Chem. Research (S) 1997 236–237 J. Chem. Research (M) 1997 1576–1594 The Utility of Phosphonium Ylides in Heterocyclic Synthesis Synthesis of Pyridazinone and Tetrahydrocinnolinone Derivatives Afaf Aly Nada,*a Ayman Wahba Erian,b Nadia Ragab Mohameda and Asma Mohamed Mahrana aNational Research Centre Dokki Cairo Egypt bDepartment of Chemistry Faculty of Science Cairo University Giza Egypt The synthesis of pyridazinone and tetrahydrocinnolinone derivatives via the reaction of phosphonium ylides with different hydrazines is accomplished; reaction of a pyridazinone derivative with Wittig reagents is also achieved.Arylhydrazones have been widely reported in the literature as reagents for the synthesis of heterocyclic compounds.1–6 Indeed they are fundamental to the syntheses of a range of pharmaceutical fungicides and solvatochromic dyes. In this paper the preparation of pyridazinones and their fused systems via reaction of phosphonium ylides with different hydrazones is reported. The starting arylhydrazones 1a–c were readily obtained by coupling the appropriate methylene reagents with different arenediazonium salts as previously reported.13,14 Compounds 1a–c reacted smoothly with each of the Wittig reagents 2a,b to give directly the corresponding pyridazinone derivatives 3a–c.The structures of 3a–c were confirmed by a thorough study of their MS and NMR data. The NMR spectrum of 3a in different solvents as well as its 13C NMR were in accordance with the structure of the product which had been previously prepared by another methodology.6 The formation of compounds 3a–c is assumed to proceed via nucleophilic addition of the phosphorus ylide 2 to the carbonyl group in 2a,b or to the imine group in 1c to give the betaine intermediate A. The latter undergoes irreversible decomposition to give B that cyclizes to give the final isolable pyridazine derivatives 3a–c via alcohol elimination (Scheme 1).Similar to 1 this synthesis was extended to the 2-arylhydrazonocyclohexane- 1,3-dione derivatives 4a–c which were readily obtained by coupling 3,3-dimethylcyclohexane- 1,5-dione (6) with the appropriate arenediazonium chlorides as reported earlier.15 The reaction of 4a–c with either 2a or 2b afforded extensively the tetrahydrocinnolinone derivatives 5a–c respectively (Scheme 2). The cinnolinone 5a was also prepared via an independent route involving the reaction of 2a,b with 3,3-dimethylcyclohexane-1,5-dione 6 in boiling dry toluene to give the olefin intermediate 7a,b. The latter afford 8a,b on coupling with benzenediazonium chloride. Compounds 8a,b cyclized on boiling in a solution of ethanol and piperidine to give the final product 5a (Scheme 2).Compounds 4a–c also reacted with 2c in boiling toluene to afford the hydroxy derivatives 9a–c (Scheme 3). Similarly the structure of 9a was further established by the reaction of dimedone 6 with 2c resulting in 7c which reacted with benzenediazonium chloride to give 8c. Upon boiling 8c in an ethanol–piperidine solution 9a was obtained (Scheme 3). The preparation of new tetrahydrocinnolinones from cyclic b-diketo derivatives was generalized. Thus treatment of compounds 10–12 with benzenediazonium chloride gave the corresponding hydrazones 13–15 respectively.13 The reaction of the phosphonium ylide 2a with compounds 13–15 proceeded in boiling dry toluene to give the corresponding new condensed tetrahydrocinnolinones 16–18 respectively together with triphenylphosphine oxide which was isolated from the reaction medium.Analogues of these compounds have already been prepared.16–18 The formation of 16–18 is assumed to proceed via the corresponding intermediate olefin e.g. 19 (Scheme 4). *To receive any correspondence. Scheme 1 Scheme 2 NNHAr O O a Ar = Ph b Ar = C6H4Me-4 c Ar = C6H4NO2-4 4 + Ph3P CHCOPh N N O Ph OH Ar a Ar = Ph b Ar = C6H4Me-4 c Ar = C6H4NO2-4 9 –TPPO toluene 2c N N O O Ph 13 MeN NMe N N O O Ph 14 O O N N O O Ph 15 O NNHPh O O MeN NMe NNHPh O O NNHPh O O O 10 11 12 O O MeN NMe O O O O O O O MeN NMe CHCO2Me NHPh N O O PhN NCl + – PhN NCl + – PhN NCl + – 16 17 18 19 N N EtO2C Me CN Ph + 2a,b N N EtO2C Me CN Ph a R¢ = Me b R¢ = Et 21 20 O CHCO2R¢ J. CHEM. RESEARCH (S) 1997 237 We also investigated the reaction of Wittig reagents 2a,b with a pyridazinone derivative.Thus reaction of 2a,b with ethyl 1-aryl-5-cyano-4-methyl-6-oxo-1,6-dihydropyridazine- 3-carboxylate 2919 in dry toluene afforded the corresponding olefins 21a,b respectively (Scheme 5). Techniques used 1H and 13C NMR MS IR elemental analysis References 22 Full text in English Received 18th April 1996; Accepted 10th January 1997 Paper F/4/00368D References cited in this synopsis 1 A. McKillop and A. J. Boulton Synthesis of Six membered Rings in Comprehensive Heterocyclic Chemistry ed. A. R. Katritzky and C. W. Reeds Pergamon Press Oxford 1984 p. 267. 2 T. Benneche G. Keilen G. Halgelin R. Oftebro and K. Undheim Acta Chem. Scand. 1991 45 177. 3 M. H. Elngadi F. M. Abdelrazek N. S. Ibrahim and A.W. Erian Tetrahedron 1989 45 4597. 4 A. W. Erian Chem. Rev. 1993 93 1991. 5 J. M. Damagala and P. Peterson Heterocycles 1989 26 1147 and references cited therein. 6 H. V. Patel K. A. Vyas S. P. Pandey F. Tavares and P. S. Fernandes Synth. Commun. 1991 21 1935. 13 M. H. Elnagdi A. W. Erian K. U. Sadek and M. A. Selim J. Chem. Res. (S) 1990 184. 14 N. S. Ibraheim M. H. Mohamed Y. Mahfouz and M. H. Elnagdi J. Prakt. Chem. 1989 331 375. 15 K. Gewald and U. Hain Synthesis 1984 62. 16 S. M. Fahmy N. M. Abed R. M. Mohareb and M. H. Elnagdi Synthesis 1982 490. 17 M. H. Elnagdi H. A. Elfahham M. R. Elmoghayar K. U. Sadek and G. E. H. Elgemeie J. Chem. Soc. Perkin Trans. 1 1982 989. 18 B. D. Schober G. Megyeri and T. Kappe J. Heterocycl. Chem. 1989 26 169. 19 M. H. Elnagdi A. M. Abdel Aal Fatma A. H. Ebtisam and M. Y. Youssef Z. Naturforsch. B. Chem. Sci. 1989 44b 683. Scheme 3 Scheme 4 Scheme 5

ISSN:0308-2342    

DOI:10.1039/a700368d

出版商:RSC    

年代:1997

数据来源: RSC