591233-95-3Relevant academic research and scientific papers
One-stage procedure of synthesis of highly reactive α-chloro-β- ketoacetals. 4-chloropyrazoles from α-chloro-β-ketodimethoxyacetals
Bozhenkov,Savosik,Mirskova,Levkovskaya
, p. 184 - 189 (2008)
Conditions were developed where the reaction of alkyl 1,2-dichlorovinyl ketones with alcohols and 1,2-dihydroxybenzenes led to the formation of the corresponding open-chain and cyclic α-chloro-β-ketoacetals. The reaction of α-chloro-β-alkylketodimethoxyac
Distinguishing features of reactions of 2-chloro- and 2,2-dichloro(bromo) vinyl ketones with alkyl- and arylhydrazines
Bozhenkov,Savosik,Larina,Klyba,Zhanchipova,Mirskova,Levkovskaya
experimental part, p. 1014 - 1023 (2009/07/05)
2-Chlorovinyl alkyl ketones react with alkylhydrazines to give mixtures of 1-R-3-R′- and 1-R-5-R′-pyrazoles: The 1-R-3-R′-pyrazoles form through the heterocyclization of 2-chlorovinyl ketone alkylhydrazones whereas in the heterocyclization into 1-R-5-R′-pyrazoles N1-alkyl-N 2-(2-acylvinyl)hydrazines are involved. The regiospecific heterocyclization of 2-chloro-and 2,2-dichlorovinyl ketones with arylhydrazines and also of 2,2-dichloro(bromo)vinyl trifluoromethyl ketones with C alkylhydrazines into pyrazoles and 5-chloro(bromo)-pyrazoles proceeds through a stage of haloenones hydrazones formation. The study of the structure of the obtained 1-alkyl-3(5)-alkylpyrazoles by means of two-dimenaional 1H and 13C NMR spectroscopy and GC-MS method made it possible to assign the proton and carbon signals of isomeric pyrazoles and to establish the diagnostic ions for the pair of 1,3-and 1,5-isomers.
