反应详情

In an argon gas stream and at −78° C., n-butyl lithium (a 1.57M hexane solution, 1.27 ml, 2.00 mmol) was added to a tetrahydrofuran (10 ml) solution of the 2-[(4-chlorophenyl)sulfonylmethyl]-1,4-difluorobenzene (606 mg, 2.00 mmol) obtained in Example 5. The temperature of the resulting mixture was then raised to room temperature. After cooling to −78° C., butyryl chloride (0.218 ml, 2.10 mmol) was added dropwise to the reaction mixture. The reaction mixture was stirred at −78° C. for 1.5 hours, and added with 1N hydrochloric acid (2.0 ml). The temperature of the mixture was then raised to room temperature. The reaction mixture was extracted with diethyl ether. The extracts were combined, washed successively with water and brine, dried over MgSO4, and concentrated. The residue thus obtained was purified by medium-pressure chromatography on a silica gel column (10% ethyl acetate-hexane). The solid thus obtained was recrystallized from hexane, whereby the title compound (330 mg, 44%) was obtained as colorless needle crystals.

1. temperatureAfter cooling to −78° C.
2. temperatureThe temperature of the mixture was then raised to room temperature
3. extractionThe reaction mixture was extracted with diethyl ether
4. washwashed successively with water and brine
5. dry with materialdried over MgSO4
6. concentrationconcentrated
7. customThe residue thus obtained
8. customwas purified by medium-pressure chromatography on a silica gel column (10% ethyl acetate-hexane)
9. customThe solid thus obtained
10. customwas recrystallized from hexane, whereby the title compound (330 mg, 44%)
11. customwas obtained as colorless needle crystals