反应详情

A solution of 5,5-dimethyl-3-trifluoromethyl-4,5,6,7-tetrahydro-benzo[c]thiophene-1-carboxylic acid methoxy-methyl-amide (14 g, 44 mmol) in diethyl ether (400 mL) is treated at it with methyl lithium (80 mL, 1.6 M in diethyl ether). Upon complete addition, the mixture is stirred at it for 15 min before it is poured onto water/ice and neutralized with aq. HCl. The ether phase is separated and the aq. phase is extracted two more times with diethyl ether (2×100 mL). The organic extracts are washed with brine, dried over MgSO4, filtered and evaporated. The crude product is purified by CC on silica gel eluting with heptane containing 20-30% of DCM to give 1-(5,5-dimethyl-3-trifluoromethyl-4,5,6,7-tetrahydro-benzo[c]thiophen-1-yl)-ethanone (9.1 g) as a yellow oil; LC-MS: tR=1.11 min, [M+1+CH3CN]=318.34; 1H NMR (CDCl3): δ 3.04 (t, J=7.0 Hz, 2H), 2.57 (d, J=1.2 Hz, 2H), 2.53 (s, 3H), 1.58 (t, J=7.0 Hz, 2H), 0.99 (s, 6H).

1. additionUpon complete addition
2. customThe ether phase is separated
3. extractionthe aq. phase is extracted two more times with diethyl ether (2×100 mL)
4. washThe organic extracts are washed with brine
5. dry with materialdried over MgSO4
6. filtrationfiltered
7. customevaporated
8. customThe crude product is purified by CC on silica gel eluting with heptane containing 20-30% of DCM