反应详情

To a solution of ethyl α-bromoisobutyrate (62 g, 0.32 mol) in DMF (500 mL) at room temperature is added potassium thioacetate (72 g, 0.63 mol). The reaction is stirred for 16 h and then concentrated under reduced pressure. The residue is diluted with a 2M aqueous HCl solution (500 mL) and extracted with ethyl acetate (3×500 mL). The organic fractions are combined, washed with brine (300 mL), dried over MgSO4, filtered and concentrated under reduced pressure. Purification by chromatography on silica eluting with heptanes/DCM provides 44 g of 2-acetylsulfanyl-2-methyl-propionic acid ethyl ester. Yield: 73%; m/z 191 [M+H]; 1H NMR (250 MHz, CHLOROFORM-d) δ ppm 1.18-1.30 (3H, m), 1.57 (6H, s), 2.27 (3H, s), 4.19 (2H, q, J=7.16 Hz)

1. concentrationconcentrated under reduced pressure
2. additionThe residue is diluted with a 2M aqueous HCl solution (500 mL)
3. extractionextracted with ethyl acetate (3×500 mL)
4. washwashed with brine (300 mL)
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customPurification by chromatography on silica eluting with heptanes/DCM