Azepinone compounds useful in the inhibition of ACE and NEP

An azepinone ester having the following formulae, or a salt thereof:

• ##STR62## where R.sup.1 and R.sup.2 are each independently hydrogen, alkyl, substituted alkyl, cycloalkyl-(CH.sub.2).sub.p -, aryl-(CH.sub.2).sub.p -, substituted aryl-(CH.sub.2).sub.p -, heteroaryl-(CH.sub.2).sub.p -, or R.sup.1 and R.sup.2 may form, together with the carbon to which they are bonded, a 3 to 7 membered carbocyclic ring, where said ring is optionally substituted by alkyl, or by aryl which is fused or bonded by a single bond to said ring;
• R.sup.3 and R.sup.4 are each independently hydrogen, alkyl, aryl, halo, or --C(O)--OR;
• R is hydrogen, alkyl, substituted alkyl, aryl-(CH.sub.2).sub.p -, subsituted aryl-(CH.sub.2).sub.p -, heteroaryl-(CH.sub.2).sub.p -, --CH(R.sup.8)--O--C(O)--R.sup.9, or ##STR63## R.sup.8 is hydrogen, alkyl, substituted alkyl, cycloalkyl-(CH.sub.2).sub.p -, aryl-(CH.sub.2).sub.p -, substituted aryl-(CH.sub.2).sub.p -, or heteraryl-(CH.sub.2).sub.p -;
• R.sup.9 is hydrogen, alkyl, alkoxy, or aryl;
• R.sup.10 is alkyl or aryl-(CH.sub.2).sub.p -;
• PG-N- denotes a protected nitrogen atom;
• R* denotes a group R other than hydrogen, or an acid protecting group other than R;
• and
• p is zero or an integer from 1 to 6.