N,N-diacylpiperazines

A compound of structural formula:

• ##STR15## or a pharmaceutically acceptable salt thereof, wherein:
• A is selected from:
• ##STR16## R.sup.1 is selected from the group consisting of:
• 1) H,
• 2) C.sub.1-8 alkyl,
• 3) C.sub.3-7 cycloalkyl,
• 4) phenyl, either unsubstituted or substituted with one or two substituents selected from:
• a) C.sub.1-4 alkyl,
• b) -halo,
• c) --OH
• d) --CF.sub.3
• e) --NH.sub.2,
• f) --NH(C.sub.1-4 alkyl),
• g) --N(C.sub.1-4 alkyl).sub.2,
• h) --CO.sub.2 H,
• i) --CO.sub.2 (C.sub.1-4 alkyl), and
• j) --C.sub.1-4 alkoxy;
• or
• 5) C.sub.1-4 alkyl-aryl, wherein the aryl is phenyl or naphthyl, either unsubstituted or substituted with one or two substituents selected from:
• a) --C.sub.1-4 alkyl,
• b) -halo,
• c) --OH,
• d) --CF.sub.3,
• e) --NH.sub.2,
• f) --NH(C.sub.1-4 alkyl),
• g) --N(C.sub.1-4 alkyl).sub.2,
• h) --CO.sub.2 H,
• i) --CO.sub.2 (C.sub.1-4 alkyl), and
• j) --C.sub.1-4 alkoxy;
• R.sup.2 is selected from the group consisting of:
• 1) --C.sub.1-6 alkyl,
• 2) --CH.sub.2 -aryl, wherein aryl is as defined in R.sup.1,
• 3) --CH.sub.2 --C.sub.3-7 cycloalkyl,
• 4) --CO.sub.2 R.sup.2a, wherein R.sup.2a is as defined below,
• 5) --CON(R.sup.2a R.sup.2b), wherein R.sup.2a and R.sup.2b are as defined below,
• 6) --SO.sub.2 N(R.sup.2a R.sup.2b), wherein R.sup.2a and R.sup.2b are as defined below,
• 7) -aryl, wherein aryl is as defined in R.sup.1,
• 8) --CO-aryl, wherein aryl is as defined in R.sup.1, and
• 9) --CO--C.sub.1-4 alkyl;
• R.sup.2a and R.sup.2b are independently selected from the group consisting of:
• 1) hydrogen,
• 2) --C.sub.1-8 alkyl,
• 3) --C.sub.1-8 alkyl-NH(C.sub.1-8 alkyl),
• 4) --C.sub.1-8 alkyl-N(C.sub.1-8 alkyl).sub.2,
• 5) -aryl, wherein aryl is as defined in R.sup.1,
• 6) --CH.sub.2 -aryl wherein aryl is as defined in R.sup.1, or
• 7) wherein --NR.sup.2a R.sup.2b may formula heterocyclic ring of the form --N(CH.sub.2 CH.sub.2).sub.2 L, wherein L is selected from the group consisting of O, S, N--C-.sub.1-4 alkyl, N-aryl, wherein aryl is as defined in R.sup.1, and N--CO--C.sub.1-4 alkyl;
• R.sup.3 is selected from the group consisting of:
• 1) --CO.sub.2 R.sup.2a, wherein R.sup.2a is as defined above,
• 2) --CON(R.sup.2a R.sup.2b), wherein R.sup.2a and R.sup.2b are as defined above,
• 3) --CH.sub.2 S--C.sub.1-4 alkyl, and
• 4) --CH.sub.2 O--C.sub.1-4 alkyl;
• R.sup.4 is independently selected from:
• 1) --H,
• 2) --C.sub.1-6 alkyl, and
• 3) --R.sup.3 ;
• R.sup.5 is selected from the group consisting of:
• 1) hydrogen,
• 2) --C.sub.1-6 alkyl,
• 3) --C.sub.2-6 alkenyl,
• 4) --C.sub.2-4 alkynyl,
• 5) halo,
• 6) --O--C.sub.1-4 alkyl,
• 7) --CF.sub.3,
• 8) --CN, and
• 9) --CH.sub.2 O--C.sub.1-4 alkyl,
• R.sup.6 is independently selected from:
• 1) H, and
• 2) R.sup.5 ;
• R.sup.7 is selected from the group consisting of:
• 1) --C.sub.1-6 alkyl
• 2) --C.sub.2-6 alkenyl,
• 3) --C.sub.2-4 alkynyl,
• 4) halo,
• 5) aryl, wherein aryl is as defined in R.sup.1,
• 6) CH.sub.2 -aryl, wherein aryl is as defined in R.sup.1,
• 7) --O--C.sub.1-4 alkyl,
• 8) --CF.sub.3,
• 9) --CN, and
• 10) --CH.sub.2 O--C.sub.1-4 alkyl;
• R.sup.8 is selected from the group consisting of:
• 1) --CO.sub.2 R.sup.9, wherein R.sup.9 is hydrogen or C.sub.6 alkyl,
• 2) 1H-tetrazol-5-yl.
• 3) --CONHSO.sub.2 R.sup.10, wherein R.sup.10 is selected from:
• a) C.sub.1-6 alkyl,
• b) --C.sub.1-6 alkoxy,
• c) aryl, wherein aryl is as defined in R.sup.1,
• d) --CH.sub.2 aryl, wherein aryl is as defined in R.sup.1, and
• e) CH(aryl).sub.2,
• 4) --SO.sub.2 NHR.sup.10,
• 5) --NHSO.sub.2 R.sup.10,
• 6) --SO.sub.2 NHCOR.sup.10,
• 7) --NHSO.sub.2 CF.sub.3, and
• 8) --SO.sub.2 NHCO.sub.2 R.sup.10.