Access to 2,3‐Unsubstituted Imidazo[2,1‐b][1,3]benzothiazole Using Ethylene Glycol as a C₂ Precursor and Subsequent Regioselective C3 Functionalization

Abstract

Synthesis of imidazo[2,1‐b][1,3]benzothiazoles by oxidative coupling of 2‐aminobenzothiazoles with vicinal diol was reported. Expectedly, a combination of potassium persulfate and TEMPO oxidized ethylene glycol to α‐hydroxy acetaldehyde, which coupled with 2‐aminobenzothiazole to afford 2,3‐unsubstituted imidazo[2,1‐b][1,3]benzothiazoles. The later was exploited as a reliable handle to access 3‐substituted imidazo[2,1‐b][1,3]benzothiazoles regioselectively.