Regioselective synthesis of salicylates and acetophenones by formal [3+3]-cyclocondensations of 3-oxoorthoesters with 1,3-bis(trimethylsilyloxy)-1,3-butadienes
Chloro(bromo)vinyl ketones and 2,2-Dichloroacrolein in Reactions with Hydrazines
作者:G. V. Bozhenkov、G. G. Levkovskaya、A. N. Mirskova、G. V. Dolgushin、L. I. Larina、P. E. Ushakov
DOI:10.1023/b:rujo.0000010172.72180.4f
日期:2003.8
Reactions of 2,2-dichlorovinyl and 2,2-dibromovinyl ketones with alkylhydrazines afford respectively 1-R-3-alkyl(aryl)-5-chloro- or 5-bromopyrazoles in preparative yields. The dichloroacrolein forms with alkylhydrazines and dimethylhydrazine only the corresponding hydrazones. Quantum-chemical calculations were performed characterizing the structure of the obtained ketones and dichloroacrolein C, alkylhydrazones, of dichloroacrolein dimethylhydrazone, of 1-alkyl-5-chloropyrazolinium halides, and 1-alkyl-5-chloropyrazoles.
Atavin,A.S. et al., Journal of Organic Chemistry USSR (English Translation), 1973, vol. 9, p. 320 - 322