A Convenient Procedure for the Formation of 2-Substituted Thiazolopyridines

Summary.

2-Substituted thiazolo[4,5-b]pyridines and thiazolo[5,4-c]pyridines are prepared in reasonable yields by a procedure involving reaction of a mixture of ortho-amino (diisopropyldithiocarbamato) pyridine, carboxylic acid, and phosphorus oxychloride. The procedure provides a more convenient route than methods involving prior formation and isolation of the acid amide and cyclisation to give the desired product. The procedure is proven to be general for a wide range of substituents.