Yield:54237-09-1 99.2%

Reaction Conditions:

with N,N,N,N,N,N-hexamethylphosphoric triamide in toluene;

Steps:

15 EXAMPLE 15

EXAMPLE 15 In a similar apparatus to Example 1, 7.2 g (0.05 mole) of 4-methylthiazole-5-carboxylic acid were suspended in 100 ml of toluene, followed by the addition of 0.02 g of hexamethylphosphoramide Under heating and reflux, phosgene was blown at a rate of 1.2 l/hr for 2.5 hours (0.13 mole). After completion of the blowing, stirring was continued for additional 2 hours. After completion of the reaction, the reaction mixture was filtered and the filtrate was concentrated to obtain 8.0 g of 4-methylthiazole-5-carboxylic acid chloride. Its purity and yield were 99.2% an d99.0%, respectively. NMR (δ^CDCl 3/TMS, ppm): 2.88(3H,s).

References:

US5136042,1992,A