Synthesis and biological activity of some 3-methyl/ethoxycarbonyl-6-arylimidazo[2, 1-b]thiazoles and their 5-bromo/5-formyl derivatives

Facile reaction of arylacylbromide 1 with 2-amino-4-methylthiazole 2 and its hindered reaction with 2-amino-4-ethoxycarbonylthiazole 3 during the synthesis of 3-methyl/ethoxycarbonyl-6-arylimidazo[2,1-b]thiazoles 8/9 are explained on the basis of electronic effects of the 4-substituent of thiazole substrate. Their bromination/formylation afforded the corresponding 5-bromo and 5-formyl derivatives. Results of preliminary screening of the target compounds reveal moderate anthelmintic and anti-inflammatory activity.