Indol-2-yl-piperazin-1-yl-methanone derivatives

A compound of formula I:

• or any pharmaceutically acceptable salt thereof, wherein:
• A is C(O) or S(O)2;
• R1 is selected from the group consisting of:
• (1) lower alkyl,
• (2) lower alkoxy,
• (3) cycloalkyl,
• (4) lower cycloalkylalkyl,
• (5) lower halogenalkyl,
• (6) phenyl unsubstituted or substituted with one to three substituents independently selected from the group consisting of lower alkyl, lower alkoxy, halogen, lower halogenalkyl and cyano,
• (7) lower phenylalkyl wherein the phenyl ring may be unsubstituted or substituted with one to three substituents independently selected from the group consisting of lower alkyl, lower alkoxy, halogen, lower halogenalkyl and cyano, and
• (8) —NR5R6, wherein R5 and R6 independently from each other are selected from the group consisting of lower alkyl, cycloalkyl, lower cycloalkylalkyl, lower halogenalkyl and lower phenylalkyl, or alternatively, R5 and R6 together with the nitrogen atom to which they are attached form a 5- or 6-membered heterocyclic ring optionally containing a further heteroatom of nitrogen, oxygen or sulfur;
• R2 is selected from the group consisting of:
• (1) hydrogen,
• (2) lower alkyl,
• (3) cycloalkyl,
• (4) lower cycloalkylalkyl,
• (5) lower hydroxyalkyl,
• (6) lower alkoxyalkyl,
• (7) lower halogenalkyl,
• (8) lower cyanoalkyl,
• (9) lower alkylsulfonyl,
• (10) lower alkanoyl,
• (11) phenylsulfonyl wherein the phenyl ring may be unsubstituted or substituted with one to three substitutents independently selected from the group consisting of lower alkyl, halogen, lower alkoxy, lower halogenalkoxy and lower hydroxyalkyl,
• (12) phenyl unsubstituted or substituted with one to three substituents independently selected from the group consisting of lower alkyl, halogen, cyano, morpholinyl, lower alkoxy, lower alkoxycarbonyl, lower halogenalkyl, lower halogenalkoxy, lower hydroxyalkyl, lower alkylsulfonyl and lower alkylsulfonylamino,
• (13) benzodioxolyl,
• (14) lower phenylalkyl, wherein the phenyl ring may be unsubstituted or substituted with one to three substituents independently selected from the group consisting of lower alkyl, halogen, cyano, morpholinyl, lower alkoxy, lower alkoxycarbonyl, lower halogenalkyl, lower halogenalkoxy, lower hydroxyalkyl, lower alkylsulfonyl and lower alkylsulfonylamino, and
• (15) heteroaryl unsubstituted or substituted with one or two substituents independently selected from the group consisting of lower alkyl, lower alkoxy, cyano, morpholinyl and halogen;
• R3 is hydrogen, halogen or methyl;
• and
• R4 is either R4a or R4b:
• wherein:
• m is 0 or 1;
• R7 is lower alkyl, cycloalkyl, or lower halogenalkyl;
• and
• R8 is lower alkyl, cycloalkyl, or lower halogenalkyl.