1,2,4-恶二唑的合成综述.pdf

Pharmaceutical Chemistry Journal Vol. 39, No. 10, 2005 DRUG SYNTHESIS METHODS AND MANUFACTURING TECHNOLOGY SYNTHESIS OF 1,2,4-OXADIAZOLES (A REVIEW) L. A. Kayukova1 Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 10, pp. 32 – 40, October, 2005. Original article submitted September 2, 2003. Methods used for the synthesis of 3,5-substituted 1,2,4-oxadiazoles are reviewed. The syntheses are based mostly on the use of primary amidoximes and acylating agents as the initial reactants. The pathway to another large group of 1,2,4-oxadiazoles proceeding from a broad spectrum of reactants is via their reactions of 1,3-dipolar cycloaddition, in particular, with primary amidoximes. The well-known reactions of amidoximes are those in- to O-acetylamidoximes (IIa, IIb); O-benzoyl derivatives volving their acylation, which have been thoroughly studied (IIc – IIf) were obtained via the reactions of amidoximes since 1920 – 1930 [1 – 3]. The majority of publications de- with benzoic acid chloroanhydrides in pyridine. The subse- voted to the chemistry of amidoximes in recent years refer to quent thermolysis of one of these products (O-acetylami- the synthesis of O-acylated amidoximes and 1,2,4-oxa- doxime IIa) leads to 1,2,4-oxadiazole III [8]. diazoles, which are among the most readily accessible heterocycles. Being bioisosteric with ester and amide groups R