General procedure for the preparation of ethyl 2-thiazolecarboxylate: a solution of 2-(trimethylsilyl)thiazole (135 g, 858.1 mmol) in toluene (1350 mL) was slowly added to a solution of ethyl chloroformate (98.4 mL, 1.03 mol) in toluene (1350 mL) over a period of 15 minutes. The reaction mixture was stirred continuously at 22°C for 2 hours. Subsequently, the reaction solution was poured into 25% (wt/wt) aqueous sodium carbonate solution (5 L) and stirring was continued for 30 min. The organic layer was separated and the aqueous layer was subjected to secondary extraction with dichloromethane (2 x 1 L). All organic layers were combined and the solvents were evaporated under reduced pressure to give ethyl 2-thiazolecarboxylate (134 g, 99% yield).ES/MS m/z 158 (M + 1)+.
