Reactivity of 7-dithiocarboxy-imidazo[2,1-b]thiazoliumbetaine with aliphatic alkylating agents

Abstract

We have reported earlier on the reactivity of 7-dithiocarboxy-3-phenyl-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with severalpara-substituted phenacyl bromides. In this work reactions of 7-dithiocarboxy-3-phenyl(or methyl)-5,6-dihydro imidazo[2,1-b]thiazolium-betaine with a series of aliphatic alkylating agents of α-halo ketone, γ-halo keto ester and α-halo ester were examined for the similar purpose. In case of α-halo ketone or γ-halo keto ester such as α-chloro acetone or ethyl 4-chloro acetoacetate new biheterocyclic compound was obtained via ring transformation reaction. However, reaction of the betaine with methyl(or ethyl) bromoacetate used as a α-halo ester, gave, instead, S-alkylated quarternary ammonium salt.