反应详情

The 5-methyl-2-mercaptobenzaldehyde (Step 1) (3.25 g, 21.3 mmol) was added to DMF (5 mL) and ethyl 4,4,4-trifluorocrotonate (4.32 g, 25.7 mmol). With stirring, K2CO3 (3.78 g, 27.3 mmol) was added causing the reaction to become a deep red. The reaction was stirred at room temperature for 20 hours, acidified with 3N HCl, diluted with ethyl acetate and washed with water, saturated NaHCO3 solution, brine, dried over MgSO4, filtered and concentrated in vacuo yielding an oil. The oil was crystallized from diethyl ether-petroleum ether to give ethyl 6-methyl-2-(trifluoromethyl)-2H-1-benzothiopyran-3-carboxylate as a light yellow solid (4.47 g, 69%): mp 93.1-94.7° C. 1H NMR (acetone-d6/300 MHz) 7.94 (s, 1H), 7.41 (s, 1H), 7.31 (d, 1H, J=7.9 Hz), 7.25 (d, 1H, J=7.9 Hz), 4.96 (q, 1H, J=8.5 Hz), 4.33 (m, 2H), 2.34 (s, 3H), 1.35 (t, 3H, J=7.0 Hz). FABLRMS m/z 309 (M+Li).

1. customthe reaction
2. stirringThe reaction was stirred at room temperature for 20 hours
3. washwashed with water, saturated NaHCO3 solution, brine
4. dry with materialdried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customyielding an oil
8. customThe oil was crystallized from diethyl ether-petroleum ether