A solution of 2-(2,8-Dimethyl-1,2,3,4-tetrahydro-pyrido[4,3-b]indol-5-yl)-1,1-diphenyl-ethanol (100 mg, 0.25 mmol) in DCM (5 mL) and DMF (2 drops) was stirred at 0-10° C. Thionyl chloride (1.55 mL, 21.46 mmol) was added and the reaction mixture was stirred at RT for 2.5 h. The solvent was removed under vacuum to obtain crude yellow solid. 1N NaOH (10 mL) was added to the reaction mixture and the desired compound extracted with EtOAc (20 mL×2). The organic layer was dried over anhydrous sodium sulfate, concentrated under vacuum to obtain the crude product (90 mg) which was purified by column chromatography on silica gel (100-200 mesh) using eluent 0-3% MeOH and DCM to obtain 15 mg product which was converted to HCL salt. 1H NMR (CD3OD, HCl salt) δ (ppm): 7.40 (m, 5H), 7.22-7.16 (m, 6H), 6.98 (m, 3H), 4.62 (d, 1H), 4.30 (m, 1H), 3.62 (m, 1H), 3.36 (m, 1H), 2.98 (s, 3H), 2.80 (m, 2H), 2.40 (s, 3H).
