摘要:

AbstractSubstituted carboxamide hydrazones have been condensed with 2,3‐butanedione and with glyoxal to form 1,2,4‐triazines; with benzaldehyde and pyridine‐2‐carboxaldehyde to yield 1,2,4‐tr

ISSN:0022-152X    

DOI:10.1002/jhet.5570070501

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractThe condensation ofo‐mercaptobenzamides with methyl acetylenedicarboxylate or methyl propiolate occurs withtransaddition of the SH to the alkyne linkage. The resulting vinyl sulfide adducts can be ring closed to 1,3‐benzothiazin‐4‐ones in excellen

ISSN:0022-152X    

DOI:10.1002/jhet.5570070502

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractCondensation of pyridoxal with the methyl ester of glycine gave the aminocoumarin analog 3‐amino‐8‐rnethyl‐2‐oxo‐2H‐pyrano[2,3‐c]pyridine‐5‐methanol (III), and not the expected aldimine. The structure of the compound was deduced by independent synthesis and by comparing its NMR spectrum with that of 3‐aminocoumarin. The new reaction provides routes for the synthesis of α4‐pyridoxylideneglycine and α4‐pyridoxyloxoacetic acid derivatives. It may also provide a model for irreversible inactivation of vitam

ISSN:0022-152X    

DOI:10.1002/jhet.5570070503

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractThe isomerization ofs‐triazolo[4,3‐a]pyridines intos‐triazolo[1,5‐a]pyridines is greatly facilitated by electron withdrawing nitro substituents in the pyridine ring and retarded by electron donating amino

ISSN:0022-152X    

DOI:10.1002/jhet.5570070504

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractDepending upon reaction conditions, 4,5‐diaminopyrimidine and acetoacetic ester gave a variety of condensation products, including the two isomeric dihydropyrimido[4,5‐b][1,4]‐diazepinones. Under conditions leading to bicyclic products, the formation of 1,5‐dihydro‐4‐methyl‐2H‐pyrimido[4,5‐b][1,4]diazepin‐2‐one (2) was strongly favored. The isomeric 3,5‐dihydro‐2‐methyl‐4H‐4‐one compound (4) was best obtained by cyclization of ethyl 3‐(4‐amino‐5‐pyrimidylamino)crotonate (3) under base catalysis. Thermal rearrangement of2and4proceeded, in each instance, with loss of the isopropenyl moiety and gave 8‐purinone. Compound4underwent ring contraction under the influence of alkoxide to yield a product which was s

ISSN:0022-152X    

DOI:10.1002/jhet.5570070505

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractSeveral tetrazole derivatives have been prepared from 7‐amino‐2‐hydroxy‐3‐phenyl‐1,8‐naphthyridine (Id). Evidence is presented to demonstrate that the tetrazole ring structure is the dominant species in the solid state and in alkaline solution while the open‐chain azido form dominates in acidic solution. In addition it has been shown that the presence of a phenyl group in a position adjacent to the tetrazole nucleus apparently stabilizes the

ISSN:0022-152X    

DOI:10.1002/jhet.5570070506

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

Abstract4‐Amino‐2,2,5,5‐tetrakis(trifluoromethyl)‐3‐oxazoline (3a) was prepared from the reaction of sodium cyanide with hexafluoroacetone and hexafluoroacetone imine, and from the reaction of hexafluoroacetone cyanohydrin with the imine. Several other oxazolines were also prepared by related reactions of other fluoroketones and imines. The proton nmr spectrum of an15N‐labeled sample of3ashows that it exists in solution primarily as the amino tautomer and not as the imino tautomer3b. Comparison of3awith the closely related, pharmacologically active 4‐amino‐2,2,5,5‐tetrakis(trifluoromethyl)‐3‐imidazoline (2) has shown large differences in ΔH of complex formation and reactivity with

ISSN:0022-152X    

DOI:10.1002/jhet.5570070507

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractHydrazoic‐sulfuric acid mixture convertedcis‐α‐phenyl‐β‐benzoylchalcone (trans‐dibenzoylstilbene,4) into 2,3‐diphenyl‐4‐benzoylquinoline (5) the structure of which was proved by debenzoylation to 2,3‐diphenylquinoline. α,β‐Diphenyl andcis‐α,β‐dibromochalcones similarly were converted respectively into 2,3,4‐triphenylquinoline (19) and 2‐phenyl‐3,4‐dibromoquinoline (20). The structure of19was shown by difference from the corresponding isoquinoline21(synthesized). Smith's mechanism for the analogous conversion ofo‐phenylbenzophenone into 9‐phenylphenanthridine through the 9‐fluorenol and the 9‐hydroazide with loss of nitrogen and ring expansion, was supported by methyl label experiments using 2‐(p‐tolyl)benzophenone which gave a 53:47 mixture of 3‐ and 8‐methyl‐6‐phenylphenanthridines. Applicability of the mechanism to the reactions with disubstitutedcis‐chalcones was shown by sulfuric acid conversions of two of these into indenol22and 2‐bromo‐3‐phenylindenone (24), respectively.trans‐Dibenzoylstilbene underwent resinification in sulfuri

ISSN:0022-152X    

DOI:10.1002/jhet.5570070508

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

AbstractA procedure for preparing the title compounds is reported. These compounds represent the first 2‐substituted‐4‐hydroxyisocarbostyrils, a structural type which could not be obtained byN‐alkylation of the previously known 2H‐4‐hydroxyisocarbostyril. Although 3‐carboxanilides in this series could not be made by aminolysis of the corresponding 3‐ester, they were successfully prepared from 4‐hydroxy‐2‐methylisocarbostyril using aryl isocyanates and sodium hydride in hexamethylphosphoramide as solvent. Evidence is presented for an enolic (“4‐hydroxy”) form of the title compounds and preference forO‐alkylation was observed. Contrary to previous reports, data was obtained to support the enolic structure of the previously

ISSN:0022-152X    

DOI:10.1002/jhet.5570070509

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY

摘要:

Abstract4‐Dicyanomethylene‐2‐phenyl‐4H‐1‐benzopyran (1) reacts with primary amines under mild conditions to give 4‐imino‐3‐alkyl‐5‐alkylimino‐2‐phenyl‐3,4‐dihydro‐5H‐[1]benzopyrano[3,4‐c]‐pyridine derivatives which, in turn, are hydrolyzed with acid to 4‐imino‐3‐alkyl‐2‐phenyl‐3,4‐dihydro‐5H‐[1]benzopyrano[3,4‐c]pyridin‐5‐ones. When more vigorous conditions are employed for the reactions of 1 with primary amines, Dimroth rearrangements take place and the products are derivatives of 4‐alkyl‐ (or aryl)amino‐5‐alkyl‐ (or aryl)imino‐2‐phenyl‐5H‐[1]benzopyrano‐[3,4‐c]pyridine. The latter compounds are hydrolyzed by acid to the corresponding 5‐pyridone derivatives. The reaction of1with piperidine gives 2‐phenyl‐4‐piperidyl‐5H‐[1]benzopyrano‐[3,4‐c]pyridin‐5‐one. Sodium methoxide reacts with1to give 3‐cyano‐2‐methoxy‐4‐(2‐hydroxyphenyl)‐6‐phenylpyridine. Two benzologs

ISSN:0022-152X    

DOI:10.1002/jhet.5570070510

出版商:Wiley‐Blackwell    

年代:1970

数据来源: WILEY