Acetic Acid → 5-t-butoxycarbonylmethyl-3-(1-ethoxycarbonyl-3-phenylpropylamino)-2-phenyl-2,3-dihydro-1,5-benzothiazepin-4(5H)-one

Participants

Reaction Conditions

Reaction Steps

1.2 g of the compound obtained in Example 20 was mixed with 2.0 g of ethyl benzylpyruvate, 20 ml of ethanol and 1 ml of acetic acid and dissolved therein by warming to 40° C. The resulting reaction mixture was stirred for 3 hours. Thereafter, a solution of 400 mg of sodium boron cyanide hydride in 10 ml of ethanol was slowly added dropwise to the reaction mixture, which was then allowed to stand overnight. After the solvent was distilled off under reduced pressure, the residue was dissolved in ethyl acetate. The resulting solution was washed with water, dried over anhydrous sodium sulfate and then concentrated under reduced pressure. The concentrate was fractionated and purified by silica gel column chromatography using a 9:1 mixture of benzene and ethyl acetate as the eluent. Thus, there was obtained 1.66 g of the desired compound.

Provenance & Evidence