1-[(INDOL-3-YL)CARBONYL]PIPERAZINE DERIVATIVES

The present invention relates to 1-[(indol-3-yl)carbonyl]piperazine derivative according to the general formula (I), wherein R represents 1-4 substituents independently selected from H, (C1-4)alkyl (optionally substituted with halogen), (C 1-4)alkyloxy (optionally substituted with halogen), halogen, OH, NH2, CN and NO2; R1 is (C5-8)cycloalkyl or (C5-8)cycloalkenyl; R2 is H, methyl or ethyl; R3, R3', R4' R4', R5, R5' and R6' are independently hydrogen or (C1-4)alkyl, optionally substituted with (C1-4)alkyloxy, halogen or OH; R6 is hydrogen or (C1-4)alkyl, optionally substituted with (C1-4)alkyloxy, halogen or OH; or R6 forms together with R7 a 4-7 membered saturated heterocyclic ring, optionally containing a further heteroatom selected from O and S; R7 forms together with R6 a 4-7 membered saturated heterocyclic ring, optionally containing a further heteroatom selected from O and S; or R7 is H, (C1-4)alkyl or (C3-5)cycloalkyl, the alkyl groups being optionally substituted with OH, halogen or (C1-4)alkyloxy; or a pharmaceutically acceptable salt thereof. The invention also relates to pharmaceutical compositions comprising said 1-[(indol-3-yl)carbonyl]piperazine derivatives, and to the use of these derivatives in the treatment of pain, such as peri-operative pain, chronic pain neuropathic pain, cancer pain, and pain and spasticity associated with multiple sclerosis.