反应详情

温度

80 °C

To a stirred suspension of potassium tert-butoxide (0.78 g, 7.00 mmol) and DMF (10 mL), thioacetic acid (0.50 mL, 7.0 mmol) was added at 0° C. The mixture was stirred for ˜5 mins and then a solution of cis methanesulfonic acid 4 tert-butoxycarbonylamino-cyclohexyl ester (1.36 g, 4.70 mmol) in DMF (4.1 mL) was added. The mixture was heated to 80° C. for 3.75 hours and was then poured into a mixture of ethyl acetate (50 mL) and water (50 mL). The phases were separated and the aqueous phase was extracted with ethyl acetate (×2). The combined organic extracts were washed with 10% aqueous citric acid solution, saturated sodium hydrogen carbonate solution, and brine, dried with sodium sulfate and concentrated under vacuum. Purification by column chromatography on silica gel (ethyl acetate/cyclohexane, 1:6) gave 325 mg (26%) of trans thioacetic acid S-(4-tert-butoxycarbonylamino-cyclohexyl) ester as an orange solid. 1H NMR (400 MHz, CDCl3) δ: 4.38 (br s, 1H), 3.42 (br s, 1H), 3.33 (m, 1H), 2.29 (s, 3H), 2.02 (m, 5H), 1.44 (s, 9H), 1.26-1.25 (m, 3H).

1. additionwas added at 0° C
2. customThe phases were separated
3. extractionthe aqueous phase was extracted with ethyl acetate (×2)
4. washThe combined organic extracts were washed with 10% aqueous citric acid solution, saturated sodium hydrogen carbonate solution, and brine
5. dry with materialdried with sodium sulfate
6. concentrationconcentrated under vacuum
7. customPurification by column chromatography on silica gel (ethyl acetate/cyclohexane, 1:6)