ChemInform Abstract: Alkylation of Pyrazoles and 1,2,4‐Triazole with cis‐ and trans‐1,4‐Dichloro‐2‐butene Under Phase‐Transfer Conditions.

Abstract

Reaction of the pyrazoles (I) with excess cis‐1,4‐dichloro‐2‐butene (II) gives the bicyclic salts (III), whereas with excess trans‐1,4‐dichloro‐2‐butene (IV) the mono‐substituted products (V) and (VI) are obtained.

Synthesis of N-(2-vinyloxyethyl)pyrazoles

“…The same we earlier observed in alkylation of pyrazoles with cis-1,4-dichloro-2-butene [5]. Compounds V3VII were converted into monomeric N-(2-vinyloxyethyl)pyrazoles VIII3X by dehydrochlorination with a super base (potassium hydroxide + DMSO), since HCl could be eliminated neither in alcoholic alkalis [6] nor in phase-transfer conditions [5,7].…”

“…Compounds V3VII were converted into monomeric N-(2-vinyloxyethyl)pyrazoles VIII3X by dehydrochlorination with a super base (potassium hydroxide + DMSO), since HCl could be eliminated neither in alcoholic alkalis [6] nor in phase-transfer conditions [5,7]. It was found that elimination is accompanied by hydrolysis yielding alcohols XIII.…”

Thermal addition of pyrazoles to but-3-enenitrile

“…The general prerequisite for the successful usage of ethylene compounds in nucleophilic addition reactions is the presence of electron-withdrawing groups at the double bond, which are activating them towards the nucleophilic attack [1][2][3][4][5][6][7][8][9][10].…”