Diisopropylamine → HCID 22276396, compound

Participants

Reaction Steps

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.

Provenance & Evidence