668484-45-5

867065-53-0

668484-45-5

General procedure for the synthesis of 2-[1-(tert-butoxycarbonyl)-4-piperidinyl]-1,3-thiazole-4-carboxylic acid from ethyl 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylate: ethyl 2-(4-(tert-butoxycarbonyl)piperazin-1-yl)thiazole-4-carboxylic acid (2.0 g) was dissolved in ethanol (10 mL) and tetrahydrofuran (10 mL) as a mixed solvents and 2 N aqueous sodium hydroxide solution (5 mL) was added. The reaction mixture was stirred at 60 °C for 2 hours. After completion of the reaction, the pH was adjusted to 1 with 1 N hydrochloric acid and a precipitate was precipitated, which was collected by filtration and dried to give a light-colored solid product (1.7 g, 94% yield).