Thioacetamide → Ethyl 2-methyl-1,3-thiazole-5-carboxylate

Temperature

56 °C

Under nitrogen atmosphere, a solution of KOtBu (11.5 g) in THF (203 mL) was cooled to 0° C., and thereto were added dropwise ethyl chloroacetate (12.5 g) and ethyl formate (7.60 g) in THF (40 mL). After the addition, the mixture was stirred at 0° C. for 3 hours, and further stirred at room temperature for 16 hours. Water and a 6N aqueous hydrochloric acid solution were added to the mixture, and the mixture was extracted with Et2O, and dried over MgSO4. The solvent was evaporated under reduced pressure to give ethyl 2-chloroformyl-propionate. Under nitrogen atmosphere, to a solution of ethyl 2-chloroformylpropionate in acetone (250 mL) was added thioacetamide (7.74 g), and the mixture was stirred at 56° C. for 6 hours, and stirred at room temperature for 16 hours. The solvent was evaporated under reduced pressure, and the residue was purified by silica gel column (hexane/ethyl acetate=12.5/1→10/1) to give ethyl 2-methyl-1,3-thiazole-5-carboxylate (5.74 g, 32%).

1. stirringstirred at room temperature for 16 hours
2. customThe solvent was evaporated under reduced pressure
3. customthe residue was purified by silica gel column (hexane/ethyl acetate=12.5/1→10/1)

ORD record

ord-c66dcea13e0e47eaa155e1aa516e5f68

Source dataset

uspto-grants-2004_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06759429B2