PURPOSE: To obtain the titled substance, by epoxidizing stereospecifically a cinnamyl alcohol, reacting the reaction product with o-nitrothiophenol, reducing it, subjecting the prepared compound to ring closure, reacting the resultant compound with a halogenated 2-(dimethylamino) ethyl, dehydrochlorinating the prepared substance.

CONSTITUTION: A cinnamoyl alcohol shown by the formula I (R1 is acyl) is stereospecifically epoxidized to give a compound shown by the formula II, which is oxidized to give a carboxylic acid, which is esterified to give a chlorohydrin derivative, which is reacted with o-nitrothiophenol to give a compound shown by the formula III. This compound is subjected to OH group protection, deacylated, methylated, reduced to give an aminophenylthio derivative, which is subjected to ring closure to give a benzothiazepine derivative shown by the formula IV, which is reacted with a halogenated 2-(dimethylamino)ethyl, acetylated in the presence of an acid catalyst under anhydrous conditions, and dehydrochlorinated to give a compound shown by the formula V.

USE: A vasodilator.