反应详情

To a solution of lithium diisopropylamide in tetrahydrofuran (10 ml) prepared from diisopropylamine (801 mg) and n-butyl lithium (5.18 ml, 1.53M in n-hexane) was added dropwise a solution of 7-(5-bromo-2-thienyl)-4-tert-butoxycarbonylperhydro-1,4-thiazepine 1,1-dioxide (2.5 g) in tetrahydrofuran (25 ml) at −50° C. under a nitrogen atmosphere. After the mixture was stirred for 15 minutes, a solution of tert-butyl bromoacetate (1.78 g) in tetrahydrofuran (5 ml) was added dropwise therein under the same condition and the reaction mixture was stirred for 30 minutes. After addition of a saturated aqueous solution of ammonium chloride, the mixture was extracted with ethyl acetate (50 ml). The extract was washed successively with 5% hydrochloric acid, a saturated aqueous solution of sodium bicarbonate and brine, dried over magnesium sulfate and concentrated in vacuo. The residue was purified by SiO2 column chromatography (eluent; hexane:ethyl acetate=5:1) to afford tert-butyl-2-[7-(5-bromo-2-thienyl)-4-tert-butoxycarbonyl-1,1-dioxoperhydro-1,4-thiazepin-7-yl]acetate (1.62 g) as an amorphous powder.

1. stirringunder the same condition and the reaction mixture was stirred for 30 minutes
2. extractionthe mixture was extracted with ethyl acetate (50 ml)
3. washThe extract was washed successively with 5% hydrochloric acid
4. dry with materiala saturated aqueous solution of sodium bicarbonate and brine, dried over magnesium sulfate
5. concentrationconcentrated in vacuo
6. customThe residue was purified by SiO2 column chromatography (eluent; hexane:ethyl acetate=5:1)