Substituted-3-indolyl-4-piperidino-alkyl heterocycles for the treatment of depression

A compound represented by the formula I:

• wherein A represents the following heterocycles:
• n is 2 to 4;
• R1, R2, R3, R4, R5, R6, R7 and R8 are each independently hydrogen, straight chain alkyl of 1 to 4 carbon atoms, branched chain alkyl of 3 to 6 carbon atoms, cycloalkyl of 3 to 10 carbon atoms, halogen, alkoxy group of 1 to 4 carbon atoms, heteroaryloxy, cycloalkoxy having 3 to 6 ring members, heterocycloalkoxy of 3 to 6 ring members selected from C, O, S and N where N may have a substituent R9, hydroxy, nitro, nitrile, amino, carboxy, alkoxycarbonyl of 1 to 4 carbon atoms, alkylcarbonyl of 1 to 4 carbon atoms, aminocarbonyl and alkylaminocarbonyl of 1 to 12 carbon atoms, straight or branched chain fluorinated alkyl of 1 to 4 carbon atoms, aryl, aryloxy, alkylaryl of 7 to 12 carbon atoms, heteroaryl, heterocycloalkyl having ring atoms selected from atom C, S, O and N where N may have a substituent R9;
• R9 is C1-C6 alkyl optionally substituted with R10, C3-C6 alkenyl or alkynyl with the proviso that a carbon bearing a double or triple bond is not bonded directly to a ring heteroatom, C6-C10 aryl optionally substituted with R10, C7-C12 alkylaryl optionally substituted with R10, heteroaryl optionally substituted with R10, alkylheteroaryl optionally substituted with R10, SO2-aryl, or SO2-alkyl;
• R10 is halogen, nitrile, alkoxy, aryloxy, aryl, heteroaryl, cycloalkyl, or heterocycloalkyl with a hetero atom selected from N, O and S, and each crystalline form and pharmaceutically acceptable salt thereof.