Cyclocondensation of β-(aryl/heteroaryl)methylaminoenones with thionyl chloride: a facile general approach for the synthesis of 2,4-bis(het)aryl-5(het)aroylthiazoles

An efficient, regioselective route to 2,4-bis(het)aryl-5(het)aroylthiazoles has been developed by cyclocondensation of thionyl chloride with novel β-(het)arylmethylaminoenones which are readily accessible by the reaction of (het)arylmethylamines with 1,3-bis(het)arylmonothio-1,3-diketones. The method allows entry to 2,4,5-trisubstituted thiazoles, with full control for the introduction of either a (het)aryl group at 2,4 positions or a (het)aroyl group at 5 position of the thiazole ring.