N-(2,4-dioxo-2,3,4,5-tetrahydro-1H-1,5-benzodiazepin-3-yl)-3-amides

A compound of the structural formula I ##STR36## where R.sup.1 and R.sup.3 are independently C.sub.1-6 alkyl branched chain;

• substituted C.sub.1-6 alkyl branched chain wherein the substitutents are selected from F, C.sub.3-8 cycloalkane, --OH, --CF.sub.3, and
• Z is
• 1) C.sub.1-6 alkyl, either straight or branch chain,
• 2) substituted C.sub.1-6 alkyl, either straight or branch chain, wherein the substitutents are selected from F, --OH, NO.sub.2,
• 2) C.sub.2-4 alkenylene, either straight or branch chain,
• 3) --(CH.sub.2).sub.m --W--(CH.sub.2).sub.n -- wherein m and n are independently 0, 1, 2, 3 or 4 and W is --O--, --S-- or --NH,
• 4) C.sub.3-6 cycloalkane,
• 5) C.sub.3-6 cycloalkylene, or
• 6) single bond;
• R.sup.2 is
• 1) phenyl, either unsubstituted or substituted with one or two substituents selected from
• a) --NO.sub.2, --OH
• b) --Cl, Br, F, or I,
• c) --CF.sub.3,
• d) --C.sub.1-3 alkyl,
• e) --C.sub.1-3 alkoxy,
• f) --CN,
• g) -methylenedioxy,
• C.sub.5-7 cycloalkyl, either unsubstituted or substituted with one or two substitutents selected from
• a) --NO.sub.2, --OH,
• b) F,
• c) --CF.sub.3,
• d) --C.sub.1-3 alkyl,
• e) --C.sub.1-3 alkoxy,
• f) --CN,
• g) -methylenedioxy,
• or pharmaceutically acceptable salts, hydrates and crystal forms thereof, which are useful as antiarrhythmic agents.