Substituted 2,4-dihydro-pyrrolo[3,4-b]quinolin-9-one derivatives useful as phosphodiesterase inhibitors

A compound of the formula (I):

• 30
• wherein
• R1 is selected from the group consisting of hydrogen, carboxy, —C(O)—C1-C6alkyl, —C(O)—C1-C6alkoxy, —C(O)—NH—C1-C6alkyl-NH2, —C(O)—NH—C1-C6alkyl-NHRA, —C(O)—NH—C1-C6alkyl-N(RA)2, —C(O)—NH2, —C(O)—NHRA, —C(O)—N(RA)2, —C1-C6alkyl-NH2, —C1-C6alkyl-NHRA, —C1-C6alkyl-N(RA)2, —NH—C1-C6alkyl-N(RA)2;
• where each RA is independently selected from the group consisting of C1-C6alkyl, aryl, C1-C6aralkyl and heteroaryl, where the aryl, aralkyl or heteroaryl may be optionally substituted with one to three RB;
• where each RB is independently selected from the group consisting of halogen, nitro, cyano, C1-C6alkyl, C1-C6alkoxy, C1-C6alkylcarbonyl, carboxyC1-C6alkyl, C1-C6alkylsulfonyl, trifluoromethyl, amino, di(C1-C6alkyl)amino, acetylamino, carboxyC1-C6alkylcarbonylamino, hydroxyC1-C6alkylamino, NHRA and N(RA)2;
• R2 is selected from the group consisting of C5-C10alkyl (optionally substituted with one to three substituents independently selected from halogen, hydroxy, nitro, amino, NHRA or N(RA)2), aryl (optionally substituted with one to three substituents independently selected from RC), cycloalkyl (optionally substituted with one to three substituents independently selected from RA), heteroaryl (optionally substituted with one to three substituents independently selected from RC), and heterocycloalkyl (optionally substituted with one to three substituents independently selected from RC);
• where RC is selected from the group consisting of halogen, nitro, cyano, C1-C6alkyl, C1-C6alkoxy, trifluoromethyl, trifluoromethoxy, NH2, NH(C1-C6alkyl) and N(C1-C6alkyl)2;
• R3 is selected from the group consisting of hydrogen, C1-C6alkyl, C1-C6alkylcarbonyl, C2-C6alkenylcarbonyl and C2-C6alkynylcarbonyl;
• b is an integer from 0 to 4;
• R4 is independently selected from the group consisting of halogen, hydroxy, carboxy, oxo, nitro, C1-C6alkyl, C1-C6alkoxy, C1-C6alkoxycarbonyl, trifluoromethyl, phenyl (wherein the phenyl group may be optionally substituted with one to three substituents independently selected from RD), phenylsulfonyl, naphthyl, C1-C6aralkyl, —O-aralkyl, (wherein the aralkyl group may be optionally substituted with one to three substituents independently selected from RD), heteroaryl (wherein the heteroaryl may be optionally substituted with one to three substituents independently selected from RD), heterocycloalkyl, NH2,
• 31
• where each RD is independently selected from the group consisting of halogen, hydroxy, carboxy, oxo, C1-C4alkyl, C1-4alkylthio, hydroxyC1-4alkyl, C1-C4alkoxy, C1-C4alkyoxycarbonyl, C1-C4alkylcarbonyl, trifluoromethyl, trifluoromethoxy, NH2, NHRA, N(RA)2, C(O)N(RA)2, acetylamino, nitro, cyano, formyl, C1-C6alkylsulfonyl, carboxyC1-C6alkyl and aralkyl;
• c is an integer from 0 to 4;
• R5 is independently selected from the group consisting of halogen, nitro, hydroxy, C1-C6alkyl, C1-C6alkoxy, —NH2, —NHRA, —N(RA)2, —ORA, —C(O)NH2, —C(O)NHRA, —C(O)N(RA)2, —NHC(O)RA, —SO2NHRA, —SO2N(RA)2, where RA is as defined above, phenyl (optionally substituted with one to three substituents independently selected from RB), heteroaryl (optionally substituted with one to three substituents independently selected from RB) and heterocycloalkyl (optionally substituted with one to three substituents independently selected from RB);
• a is an integer from 0 to 1;
• Y selected from the group consisting of —C1-C6alkyl-, —C(O)—, —(C1-C6alkyl)carbonyl-, —(C2-C6alkenyl)carbonyl-, —(C2-C6alkynyl)carbonyl-, -carbonyl(C1-C6alkyl)-, -carbonyl(C2-C6alkenyl)-, —C(O)O—(C1-C6alkyl)-, —C(S)—, —SO2—, —(C1-C6alkyl)sulfonyl-, -sulfonyl(C1-C6alkyl)-, —C(O)NH—, —C(O)NH—(C1-C6alkyl)-, —C(O)(C3-C7cycloalkyl)- and —(C3-C7cycloalkyl)—C(O)—;
• 32
• is selected from the group consisting phenyl, furyl, thienyl and pyrrolyl;
• 33
• is selected from the group consisting of aryl, heteroaryl, cycloalkyl and heterocycloalkyl;
• provided that when R1 is hydrogen, R3 is hydrogen, b is 0, c is 0, a is 1, Y is —CH2—,
• 34
• is phenyl and
• 35
• is phenyl, then R2 is not trimethoxyphenyl
• or a pharmaceutically acceptable salt thereof.