The invention relates to indole derivative having the general Formula I wherein A represents a 5-membered aromatic heterocyclic ring, wherein X1, X2 and X3 are independently selected from N, O, S and CH； Y represents CH2, O, S or SO2； R1 is H, (C1-4)-alkyl, (C1-4)alkyloxy, CN or halogen； R2, R2', R3, R3', R4, R4', R5 and R5' are independently hydrogen, (C1-4)alkyl (optionally substituted with OH) or CO-OR8； or one pair of geminal substituents R3 and R3' or R5 and R5' together represent a keto group, and the others are all hydrogen or (C1-4)alkyl； or R2 and R5 together represent a methylene or an ethylene bridge, and R2', R3, R3', R4, R4' and R5' are hydrogen； n is 1 or 2； R6 is H, (C1-4)alkyl (optionally substituted with OH, (C1-4)alkyloxy, CO-NR9R10, CO-OR11 or 1,2,4-oxadiazol-3-yl), SO2NR12R13 or COOR14； R7 is H or halogen； R8 is (C1-4)alkyl； R9 and R10 are independently hydrogen, (C1-4)alkyl or (C3-7)cycloalkyl, the alkyl groups being optionally substituted with OH or (C1-4)alkyloxy； R11 is H or (C1-4)alkyl； R12 and R13 are independently H or (C1-4)alkyl； R14 is (C1-6)alkyl； or a pharmaceutically acceptable salt thereof, as agonists of the cannabinoid CB1 receptor, which can be used in the treatment of pain such as for example peri-operative pain, chronic pain, neuropathic pain, cancer pain and pain and spasticity associated with multiple sclerosis.
