Ethyl chloroformate → HCID 86695275, compound

Participants

Reaction Steps

Ethyl chloroformate (9.8 g, 83.6 mmol) was added to a solution of 2-(ethoxycarbonyl)thiazole-5-carboxylic acid (Intermediate X, 13 g, 64.67 mmol), TEA (9.79 g, 97.01 mmol) in acetone (130 mL) at −20° C., stirred for 1 h, then a solution of NaN3 (5.4 g, 83.6 mmol) in water (15 mL) was added and stirred at RT for 30 mins. After completion, the solvent was evaporated, the crude residue was diluted with water (150 mL) and extracted with EtOAc (2×150 mL). The combined extracts were washed with water (100 mL), brine (100 mL), dried over anhydrous Na2SO4, filtered and evaporated to afford Ethyl 5-(azidocarbonyl)thiazole-2-carboxylate (11 g crude) as brown liquid. The crude was carried to next step without further purification.

Provenance & Evidence