摘要:

Abstract3‐Dcazacytosine (4‐amino‐2‐pyridone,3), 3‐doazauracil (4‐hydroxy‐2‐pyridone,5), 3‐deaza‐cytidine (4‐amino‐1‐β‐D‐ribofuranosyl‐2‐pyridonc,9), and 3‐deazauridine (4‐hydroxy‐1‐β‐D‐ribo‐furanosyl‐2‐pyridone,11) were prepared in high overall yields from 1‐methoxy‐1‐buten‐3‐yne (1). Ethyl 3,5,5‐triethoxy‐3‐pentenoate (2), obtained from acylatioti of 1 with diethyl carbonate and subsequentin situconjugate addition of ethoxide, was cyelized with ammonia to provide3. Diazotization of 3 and subsequentin situhydroxydediazotization afforded5. Nucleoside9was obtained from the stannic chloride‐catalyzed condensation of bis‐trimethylsilylated3and 1‐O‐acetyl‐2,3,5‐tri‐O‐benzoyl‐β‐D‐ribofuranose (7), followed by ammonolysis of the blockin

ISSN:0022-152X    

DOI:10.1002/jhet.5570140801

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractLes effets de substituant sur l'équilibre azido/tétrazole ont été étudiés par résonance magnétique du proton dans deux solvants deutériés (chloroforme et diméthylsulfoxyde) dans le cas des azidothiazoles, benzothiazoles, thiadiazoles et isoxazoles. Pour les dérivés du thiazole, on trouve une excellente relation de Hammett, aussi bien pour les substituants en position 4 qu'e

ISSN:0022-152X    

DOI:10.1002/jhet.5570140802

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractGrǎce au choix de certains paramétres réactionnels, de la réaction de (usion acido‐catalysée, notamment du pourcentage de catalyseur, nous avons synthétisé divers nucléosides des séries benzotriazole et benzimidazole. Cette approche nous a permis d'obtenir pour la première fois les nucléosides N‐2 substitués ainsi que les anomères α substitutés en N‐1 correspondant à ces aglycones. Nous avons ainsi montré qu'il était possible d'augmenter la sélectivité de la réaction

ISSN:0022-152X    

DOI:10.1002/jhet.5570140803

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractL'étude cinétique de la substitution desN‐méthyl‐halogénotriazoles‐1,2,4 isoméres par la pipéridine et l'ion méthoxyde rnontre que l'isomère méthyl‐1 halogéno‐5 est plus réactif que lisomère mèthyl‐4 halogéno‐3, le moins réactif étant l'isomère mèthyl‐1 halogéno‐3. L'applica‐tion de diverses méthodes de calcul théoriques montre que l'examen des charges frontières et le modèle à liaison délocalisée traduisctit le mieux les différence

ISSN:0022-152X    

DOI:10.1002/jhet.5570140804

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractCondensation of 1‐methyl‐3,4‐dihydrobenzo[b]thieno[2,3‐c]pyridine (6) with nicotinic acid in the presence of ynamine (12) gave 2‐nicotinyl‐1,2,3,4‐tetrahydro‐1‐methylenebenzo[6]thicno‐|2,3‐c]pyridine (13). Photocyclization of the enamide (13) afforded thia‐analog of naueléfine (15). Thia‐analogs of angustidine (19), and nauclétine (27) were prepared similary through photocyclization of the enamides18and26, respectively. Reduction of27with sodium boro‐hydride gave th

ISSN:0022-152X    

DOI:10.1002/jhet.5570140805

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractAliphatic selenonesters react witho‐phenylenediamine,o‐aminophenol ando‐aminothiophenol and their derivatives to form benzimidazole, benzoxazole and benzothiazole derivatives, respectively. The mass and nmr spectra of the mentioned compounds were st

ISSN:0022-152X    

DOI:10.1002/jhet.5570140806

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractThe rates of piperidino substitution of some 2‐L‐3‐nitrothiophenes (I) and 2‐L‐5‐nitrothiophenes (II) (L = Cl, Br, I, OC6H4NO2‐p, and SO2Ph) have been measured in methanol and in benzene at various piperidine concentrations. The reactivity of compounds (I) is not affected by the piperidine concentration in both methanol and benzene, except for the case of L = I (Ic). Probably due to association effects, the reactivity of Ic in benzene decreases as the piperidine concentration is increased. The reactions of compounds II follow overall second order kinetics in methanol while in benzene a different behaviour is observed as a function of the nature of the leaving group. In fact, the piperidino substitutions of IIa‐c (L = Cl, Br, I) are mildly accelerated at high piperidine concentrations (a moderate solvent effect); on the contrary the reactivity of IId and e shows a strong dependence on the piperidine concentration, pointing out a genuine

ISSN:0022-152X    

DOI:10.1002/jhet.5570140807

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractThe preparation and reaction of 1,3,2‐benzodioxa‐ and 1,3,2‐benzoxathiarsoles (IIa‐b) are described. Spiran derivatives Va‐c are obtained by treating IIa‐b with Ia‐b and triethylamine, while the reaction of IIa‐b with sodium hydroxide, ethoxide andp‐cresolate gives the compounds VIa‐b, VIIa‐b and VIIIa‐b, that can evolve to Xa‐b. Reaction of IIa‐b with sodiump‐toluenethio‐late andn‐butyllithium gave the compounds IXa‐b and XIa‐b respectively. The structure of the prepared compounds has been determined by elem

ISSN:0022-152X    

DOI:10.1002/jhet.5570140808

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractThe reaction of nucleophilic and non‐nucleophilic bases wtih 2‐carbamoyl‐3‐(γ‐chloropropyl)‐1‐indenone (5) have been investigated. Condensation of γ‐chlorobutyrophenone with malono‐nitrile afforded α‐cyano‐β‐(3‐ehloropropyl)cinnamonitrile which was cyclized in concentrated sulfurie acid to produce5. Two other products obtained from the cyclization reaction were 2‐carbamoyl‐3‐(γ‐ehloropropylidene)‐1‐indanone (4) and α‐carbamoyl‐β‐(3‐chloropropyl)cinnam‐amide.Treatment of a solution of 4 in ethyl acetate with piperidine resulted in cyclization of the γ‐chloropropyl side chain to give 2‐carbamoyl‐3‐cycIopropyl‐1‐indanone. The same compound was obtained in improved yield by the treatment of4or5with sodium hydroxide solution. The reaction of dirnethylamine with5in benzene gave initial Michael addition of the amine followed by internal alkylation of the carbanion so formed to yield 3a‐dimethylamino‐2,3,3a,8‐tetrahydro‐8‐oxoeyclopent[a]indene‐8a(lH)earboxamide (7a). Similarly addition of ammonia, pyrrolidine, piperidine, benzenethiol,p‐toluenethiol, 2‐naphthalenethiol and nitromethane to the indenone I gave respective analogs of type7.Treatment of 5 with sodium cyanide in aqueoust‐butyl alcohol resulted in a similar Michael addition followed by internal alkylation. In addition, cyclization between the nitrile and the carbamoyl functions occurred in the same step to give 2‐oxo‐4‐imino‐7,8‐benzo‐3‐aza[3.3.3]‐propellan‐6‐one (13a). Hydrolysis of the iminopyrrolido ring in13ato the corresponding suecin‐irnide gave 2,4‐dioxo‐7,8‐benzo‐3‐aza[3.3.3]propellan‐6‐one (13b). Reactión of13bwith methyl iodide, allyl bromide, benzyl bromide, and diethyluminoethyl chloride afforded the correspondingN‐alkylated products. A similar sequence starling with δ‐ehlorovalerophenone led to 5,6‐fused ring systems, including a [4.3.3

ISSN:0022-152X    

DOI:10.1002/jhet.5570140809

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY

摘要:

AbstractN‐Cyanoacetyl pyrrolidine, piperidine and morpholine reacted with ethyl phenylpropiolate to give the rearranged Michael addition products III. Some interesting results obtained from the bromination, hydrolysis and reduction of III are reported. 2‐Thiophene and 2‐furaneaceto‐nitriles reacted with ethyl phenylpropiolate to give the Claisen addition products XVIII. Reaction of either III or XVIII with hydrazine hydrate, phenylhydrazine and hydroxylamine hydrochloride afforded 3‐phenylpyrazol‐5‐one, 1,3‐diphenylpyrazol‐5‐one and 3‐phenylisoxazol‐5‐one together with the appropriate starting cyanoacetyl or cyanomethylene compounds, respectively. The mechanism for the formation of the various reaction products beside the ir and nmr spect

ISSN:0022-152X    

DOI:10.1002/jhet.5570140810

出版商:Wiley‐Blackwell    

年代:1977

数据来源: WILEY