Benzothiazepine vasodilators having aralkyl substitution

A benzothiazepine of the following formula (I):

• ##STR7## wherein X is a hydrogen atom or a halogen atom;
• R.sup.1 is a phenyl ring which is unsubstituted or independently substituted by 1 to 3 of lower alkyl, lower alkoxy or halogen;
• R.sup.2 is a hydrogen atom or a lower alkanoyl group;
• Y is a straight chain alkylene group of about 2 or 3 carbons;
• R.sup.3 is lower alkyl;
• R.sup.4 is independently lower alkyl;
• p is the integer 0, 1, 2 or 3;
• Alk is a straight chain alkylene of about 2 to 4 carbons;
• R.sup.5 is independently hydroxy, alkyl or phenyl;
• q is 0, 1 or 2 or 3 if Alk is alkylene of about 2 to 4 carbons;
• and
• Ar is a phenyl, phenoxy, thiophenoxy, naphthyl or a 5- or 6-membered heterocyclic aromatic ring which rings may be substituted independently by one or more of alkyl, alkoxy, alkylthio, hydroxy, halogen, fluoroalkyl, nitro, amino or dialkylamino or by methylenedioxy at adjacent ring carbon, and the pharmaceutically acceptable acid addition salts and quaternary ammonium compounds thereof.