Hantzsch reaction of 3‐(2‐bromoacetyl)tropolone. Synthesis of 3‐(4‐thiazolyl)tropolones

Abstract

Abstract 3‐Acetyltropolone was brominated with phenyltrimethylammonium tribromide to afford 3‐(2‐bromoacetyl)‐tropolone ( 2 ), whose reactions with thiourea, thioformamide, and ammonium dithiocarbamate gave respectively 3‐(2‐amino‐4‐thiazolyl)‐, 3‐(4‐thiazolyl)‐, and 3‐(2‐mercapto‐4‐thiazolyl)tropolone. In a similar manner, compound 2 was treated with six 1‐substituted 2‐thioureas and three thioamides to give the corresponding 3‐(4‐thiazolyl)tropolone derivatives.