A single-step preparation of thiazolo[5,4-b]pyridine- and thiazolo[5,4-c]pyridine derivatives from chloronitropyridines and thioamides, or thioureas

A one‐step synthesis of thiazolo[5,4‐b]pyridines from an appropriately substituted chloronitropyridine and thioamide, or thiourea, is presented. In particular, the reaction was used to prepare a large number of 6‐nitrothiazolo[5,4‐b]pyridine derivatives, bearing hydrogen, alkyl, substituted alkyl, cycloalkyl, aryl, heteroaryl, and amine substituents at the 2‐position. The reaction could also be extended to produce a thiazolo[4,5‐c]pyridine derivative and thiazolo[5,4‐b]pyridines with alternative substituents on the pyridinoid ring. J. Heterocyclic Chem., (2009).