Synthesis of some new 5- substituted of 2-aminothiazoles: A new approach

Mahmood Kamali

Abstract

Halogenation of 2-aminothiazoles produces 2-amino-5-halothiazoles via an addition-elimination mechanism. Also the 2-amino-5-halothiazole can undergo nucleophilic substitution reaction in which halides is displaced by strong nucleophiles. In this study, was described synthesis of 5-substituted-2-aminothiazoles (5-aminogroup-2-amino-4- phenylthiazoles and bis(2-amino-4-substituted thiazole) sulfides), directly from 2-aminothiazoles via a two-step reaction (halogenation/nucleophilic substitution protocol). These syntheses were performed by three approaches (I: reaction of thiazoles and thiourea by I2/H2O/EtOH, II: reaction of thiazoles and thiourea or amine by Br2/NaHCO3/DMF, III: reaction of thiazoles and thiourea or amine using CuBr2/Amine/CH3CN). The main advantages of these approaches are that the reaction is fast, high yields, does not involve workup and isolation of halogenated intermediate.