摘要:

AbstractNewer techniques of phosphole synthesis, particularly those which lead to simple phospholes substituted with active functional groups, are briefly surveyed. A detailed account of chemical, physico‐chemical, spectroscopic and theoretical studies related to the phosphole aromaticity problem is given and the present conflicting position is discusse

ISSN:0022-152X    

DOI:10.1002/jhet.5570130101

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractTheo‐diamine, 3,4‐diamino‐1,2,5‐thiadiazole (2), was synthesized from 3,4‐dichloro‐1,2,5‐thiadiazole (3) hy three methods. Aqueous glyoxal cyclized2into [1,2,5]thiadiazolo[3,4–6]‐pyrazine (14). 3,4‐Dichloro‐1,2,5‐thiadiazole 1,1‐dioxide (18) reaeted with2to give 1,3‐dihydro‐bis[1,2,5]thiadiazolo[3,4‐b:3′,4′‐e]pyrazine 2,2‐dioxide (19). The reaction of2with selenium oxyehloride led to [1,2,5]selenadiazolo[3,4‐c] [1,2,5]thiadiazole (12). Ring closure of 2,3‐diaminoquinoxaline (4) with thionyl chloride or selenium oxychloride gave [1,2,5]thiadiazolo‐[3,4‐b]quinoxaline (21) and [1,2,5]selenadiazolo[3,4‐b]quinoxaline (22), respectively. Sulfurous acid reduced21to the 4,9‐dihydro derivative23, which was reoxidized to21with chloranil. Aqueous hase hydrolyzed21to4viathe hydrated intermediate24. Aqueous glyoxal cyclized4to the covalent hydrate of pyrazino[2,3‐b]quinoxaline (26),27, which was dehydrated to26. Compound26underwent rapid addition of two

ISSN:0022-152X    

DOI:10.1002/jhet.5570130102

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractReactions of 1‐benzoylimino‐4‐phenylquinazolinium (I), 1‐benzoylimino‐3‐phenylquinox‐alinium (II), and 3‐benzoylimino‐1‐phenylphthalazinium betaines (III) with nucleophiles (hydroxide and cyanide ions) and 1,3‐dipolarophiles (acetylenic esters and maleimides) were investigated. Heating I in aqueous alkali gave 3‐phenylindazole, while similar treatment of II and III resulted in the formation of 1‐benzoylamino‐2‐oxo‐3‐phenylquinoxaline and 2‐benzoylamino‐1‐oxo‐4‐phenylphthalazine, respectively. Reaction of II and III with cyanide ion afforded 2‐cyano‐3‐phenylquinoxaline and 1‐cyano‐4‐phenylphthalazine in high yields, respectively. 1,3‐Dipolar cycloaddition reactions of I and III with dimethyl acetylenedicarboxylate and ethyl propiolate afforded primary 1:1 cycloadducts, while the reaction of II with dimethyl acetylenedicarboxylate gave a product which is formed by ring opening of a primary adduct. The reaction of I‐III withN‐methyl andN‐phenylmaleimides afforded the corresponding primary 1:1 cycloadducts in high yields, whose ster

ISSN:0022-152X    

DOI:10.1002/jhet.5570130103

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractHydrogenation of the homoproaporphine (IV) over platinum oxide gave a mixture of the cyclohexanols VIIa and VIIb. In contrast, reduction of IV on palladium provided the cyclo‐hexanone VI, which was also obtained from VIIb by oxidation. Treatment of the cyclohexanols VIIa and VIIb under hydrogen on platinum oxide afforded the same mixture of VIIa and VII

ISSN:0022-152X    

DOI:10.1002/jhet.5570130104

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractThe preparation and oxidation of 2,3‐dihydroindazoles to 1H, 2Hor 3H‐indazoles is described. A method for the synthesis of indazole 2‐oxides has been found. Oxidation of 2‐acetyl‐2,3‐dihydro‐3,3‐disubstituted indazoles5aand5cgave quinoid compounds20a, 20b, 24aand24b, which could be isomerized to 3H‐indazoles upon removal of the acetyl group. A quinoid compound21was also obtained on treatment of5awith t

ISSN:0022-152X    

DOI:10.1002/jhet.5570130105

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractThe synthesis of some 2‐amino‐1,8‐naphthyridine derivatives substituted in the 5‐ and/or 7‐positions with trifluoromethyl is described along with their conversions to the corresponding 1,8‐naphthyridin‐2(1H)ones. A modified procedure for oxidizing electron‐deficient heterocyclic compounds to theirN‐ox

ISSN:0022-152X    

DOI:10.1002/jhet.5570130106

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractEthyl 2‐amino‐4,6‐di(trifluoromethyl)nicotinate was prepared and its use as an intermediate in the synthesis of two 3‐pyridyl‐5,7‐di(trifluoromethyr)‐1,8‐naphthyridin‐2(1H)ones is presented. A dimer of 2‐amino‐4,6‐di(trifluoromethyl)nieot

ISSN:0022-152X    

DOI:10.1002/jhet.5570130107

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractReaction of phenylglyoxalyl bromide arylhydrazones (III) with thiourea in ethanol produces 2‐amino‐4‐phenyl‐5‐arylazothiazoles (XI) instead of the expected 2‐benzoyl‐4‐aryl‐5‐imino‐Δ2−1,3,4‐thiadiazolines (V) obtained from III and potassium thiocyanate. Phenacyl thiocyanate (IV) couples with diazotized anilines to give V. The mechanisms of formation of V and XI from VI and III, respectively, are postulated. Nitrosation of V gives the correspondingN‐nitroso derivatives (VII), which decompose upon refluxing in xylene to give 2,4‐disubstituted Δ2−1,3,4‐thiadiazolin‐5‐ones (VIII). The thiadiazolines V give the respectiveN‐aeyl derivatives IX and X with acetic a

ISSN:0022-152X    

DOI:10.1002/jhet.5570130108

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractAlkaline treatment of 2′‐benzoyl‐2‐(N‐carbophenoxy‐N‐hydroxyamino)‐4′‐chloroacetanilide (10) and its corresponding acetate6afforded respectively 5‐(2‐benzoyl‐4‐chlorophenyl)‐3‐hydroxy‐hydantoic acid (12) and 6‐chloro‐4‐phenylquinazolone (13). A study of the course of the reaction was carried out with the corresponding compounds that are devoid of the 2‐benzoyl group. An elucidation of the rearrangement is based on the isolation and independent sy

ISSN:0022-152X    

DOI:10.1002/jhet.5570130109

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY

摘要:

AbstractMixtures of 2,5‐diaryl‐1,4‐dithiin 1,1,4,4‐tctroxides and selenium were subjected to heat and afforded 2,5‐diarylselenophenes. Pyrolysis of 2,5‐diaryl‐1,4‐dithiin 1,1,4,4‐tetroxides led to the formation of a mixture of 1,2,4‐ and 1,

ISSN:0022-152X    

DOI:10.1002/jhet.5570130110

出版商:Wiley‐Blackwell    

年代:1976

数据来源: WILEY