Triethylamine → tert-butyl 3(R)-[1(R)-ethoxycarbonyl-6-phthalimidohexyl]amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetate

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Reaction Steps

In 100 ml of acetonitrile are dissolved 2 g of tert-butyl 3(R)-amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetate and 7.4 g of ethyl 2-bromo-7-phthalimidoheptanoate, and 0.85 g of triethylamine is added to the solution. After the mixture is heated at 80°-100° C. for 2 days, the mixture is concentrated under reduced pressure, diluted with 100 ml of water and extracted with 200 ml of ethyl acetate. The ethyl acetate layer is dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The resulting oily substance is separated and purified by silicagel column chromatography (hexane:ethyl acetate=2:1) to give from the first fraction 1.0 g of tert-butyl 3(R)-[1(R)-ethoxycarbonyl6-phthalimidohexyl]amino-4-oxo-2,3,4,5-tetrahydro-1,5-benzothiazepine-5-acetate as a colorless oil.

Provenance & Evidence