摘要:

AbstractThe Synthesis of novel 1‐substituted 3‐anilino‐4‐diethylaminomethyl‐5‐oxo‐3,4‐dehydro‐piperidines and 2‐substituted 1,2,3,5,6,11‐hexahydro‐5‐phenyl‐4H‐pyrido[3,4‐b][1,5]benzo diazepin‐4‐ones from the β‐arylaminovinylketones derived fromN‐substi

ISSN:0022-152X    

DOI:10.1002/jhet.5570170101

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractThree ethynyl substituted phenylphthalimides were prepared and characterized by high pressure liquid chromatography, differential scanning calorimetry, and mass spectroscopy. When the preparation ofN‐(4‐ethynylphenyl)phthalimide was attempted by the thermal cyclodehydration ofN‐(4‐ethynylphenyl)‐2‐carboxybenzamide,N‐(4‐acetylphenyl)phthalimide was obtained as the major component. This unusual hydration of an ethynyl group was investigated and a mechanism was propose

ISSN:0022-152X    

DOI:10.1002/jhet.5570170102

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractA much improved synthesis of the heretofore difficultly obtainable 2,6‐diaminopyrazine(4)was afforded by the low‐pressure catalytic hydrogenation (palladium on carbon) of 2,6‐diazido‐pyrazine(2); reaction of 2,6‐dichloropyrazine(1)and sodium azide gave2in 84% yield. The outcome of the reduction was found to be solvent dependent: 1,2‐dimethoxyethane containing aqueous ammonia gave4in 83% yield; 1,2‐dimethoxyethane alone gave 5‐aminotetrazolo[1,5‐a]‐pyrazine(3)in 26% yield. Additional alternative syntheses of3and4are described. A number of acyl and azo derivatives of4were prepared. Reactions of2with dimethyl acetylenedicarboxylate and ethyl acetate (base catalyzed) leading tovic‐triazole derivativ

ISSN:0022-152X    

DOI:10.1002/jhet.5570170103

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractThe synthesis and physico‐chemical properties of a new 7‐amino‐8H‐8‐oxo‐oxazolo[4,5‐b]‐phenoxazine ring system(8aand8b)are reported. These tetracyclic heteroaromatic rings posses an extra oxazolo ring fused to the phenoxazinone chromophore observed in actinomycin D(1b).These tetracyclic compounds(8a‐8b)possess a structure in which the orientation of the A and B rings in1bare “reversed”. Since DNA binding and the resulting specificity of the antitumor antibiotic1bis believed to depend on the spatial orientation of P(α) and P(β) relative to the functions on the B ring of1b, these new compounds represent a novel approach for investigati

ISSN:0022-152X    

DOI:10.1002/jhet.5570170104

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractReductive cyclizations ofN‐[2‐(2‐pyridyl)ethyl]imides were accomplished by employing a palladium on carbon catalyst in ethanolic acetic acid as the hydrogenation medium. Reduction of the correspondingN‐[2‐(2‐quinolyl)ethyl]imides ceased at the 1,2,3,4‐tetrahydroquinolyl stage. Controlled reduction of the tetrahydroquinolyl imides with sodium borohydride gave amido alcohols which afforded bridgehead nitrogen heterocycles upon cyc

ISSN:0022-152X    

DOI:10.1002/jhet.5570170105

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractHydroxylamine adds reversibly to C‐6 of uracil basesviaa multistep mechanism. Equilibrium constants measured at severalpH values, 25°, μ = 3.0Mare: uracil, 0.25M−1; 5‐iodouracil, 0.30M−1, 5‐bromouracil, 0.24M−1, 5‐chlorouracil, 0.06M−1and 5‐fluorouracil, 5.11M−1. The kinetics of hydroxylamine addition to both 5‐bromo‐and 5‐iodouracil are complex. At low hydroxylamine buffer concentrations, the rate constants are second‐order with respect to hydroxylamine buffer but at higher concentration a first‐order dependence is approached. Hydroxylamine elimination from 5‐iodo‐6‐hydroxylamino‐5,6‐dihydrouracil is subject to general base catalysis by tris(hydroxy‐methyl)aminomethane but at higher concentrations the rate constants are not proportional to the concentration of general base. This reaction is subject to solvent effects where increasing ethanol concentration depresses the rate when measured at constantpH. These kinetics can be rationalized in terms of a multistep reaction pathway in which hydroxylamine addition to C‐6 of the halogenated uracil precedes general acid catalyzed proton transfer to C‐5 yielding the

ISSN:0022-152X    

DOI:10.1002/jhet.5570170106

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractCycloaddition of sulfene toN,N‐disubstituted 4‐amino‐3‐methyl‐3‐buten‐2‐ones(III)occurred in fair to good yield only in the case of aliphaticN‐substitution to give 4‐dialkylamino‐3,4‐dihydro‐5,6‐dimethyl‐1,2‐oxathiin 2,2‐dioxides, whereasN,N‐disubstituted 1‐amino‐1‐penten‐3‐ones(II)did not react at all. Cycloaddition of dichloroketene toII, IIIandN,N‐disubstituted 4‐amino‐3‐buten‐2‐ones occurred only in the case of the methylphenylamino derivative, giving in good to moderate yield 6,(5)(di)alkyl‐3,3‐dichloro‐3,4‐dihydro‐4‐methylphenylamino‐2‐Hpyran‐2‐ones, which were dehydrochlori

ISSN:0022-152X    

DOI:10.1002/jhet.5570170107

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractLine route nouvelle et générale pour préparer les carboxythiazolo dioxo‐2,5 pipérazines est decrite. Dansles reactions de formation du cycle de la dioxo‐2,5 pipérazine, laNéthoxycarbonyle éthoxy‐2 dihydro‐1,2 quinoléine (EEDQ) a été utilisée comme agent d'activation. Par cette méthode le butoxycarbonyl‐9 diméthyl‐7,7 dioxo‐2,5 thia‐8 diaza‐1,4 bicyclo[4,3,0]nonane(6)et le car‐boxy‐9 dimèthyl‐8,8 dioxo‐2,5 thia‐7 diaza‐1,4 bicyclo[4,3,0]nonane(8)ont été obtenus, avec un rendement quasi quantitatif, en utilisant la carboxy‐4 butoxycarbonyl‐2 diméthyl‐5,5 thiazolidine(4)comme produit de départ. L'ester6a été hydrolysé avec de l'hydroxyde de barium en acide correspondant7et l'acide8traité avec du diazométhane a donné l'ester9. L'ester6a été synthé‐tisé aussi à partir de l'ester éthylique de laN‐(butoxycarbonyl‐2 carboxy‐4 diméthyl‐5,5 thiazoli‐dine)glycine(10). Les données spectroscopiqu

ISSN:0022-152X    

DOI:10.1002/jhet.5570170108

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractLes[α‐tétrahydropyrannyloxy]‐2 tétrahydropyrones‐3(3)se photolysent en tétrahydropyrone‐3(6)et δ‐valérolactone(7)avec des vitesses différentes selon leurs structures (S*, R*) ou (S*, S*) déterminées par rmn et filiation chimique avec les [α‐tétrahydropyrannyloxy]‐2 tétrahydro‐pyra

ISSN:0022-152X    

DOI:10.1002/jhet.5570170109

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY

摘要:

AbstractL'étude de la réaction d'hydrogénation d'isoquinoléines selon Birch a permis de mettre au point les conditions permettant d'obtenir une dihydrogénation ou une tétrahydrogénation de Phomocycle. L'application à un dérivé de la diaza‐8,13 oestrone a permis de mettre en évidence le rôle d'une fonction amine pipéridinique lors de la tétrahydrogénation. Cette étude a conduit à la synthèse de diaza‐8,13 19‐nor androsténone‐3 et de diaza‐8,13 19‐nor androstène‐4 one‐3 possè‐

ISSN:0022-152X    

DOI:10.1002/jhet.5570170110

出版商:Wiley‐Blackwell    

年代:1980

数据来源: WILEY