A solution of 2-(2,8-dimethyl-1,2,3,4-tetrahydro-pyrido[4,3-b]indol-5-yl)-1-phenyl-propan-1-ol (100 mg, 0.29 mmol) in DCM (5 mL) and DMF (2 drops) was stirred at 0-10° C. Thionyl chloride (0.8 mL, 11.02 mmol) was added and the reaction mixture stirred at RT for 2 h. The solvent was removed under vacuum to obtain the crude as a dark brown solid, which was dissolved in NMP (2 mL) and stirred for 5 min. Powdered KOH (167 mg, 2.99 mmol) was added to the reaction mixture and the contents heated at 85° C. for 45 min. After completion of reaction, the reaction mixture was poured in water and the desired compound extracted with EtOAc (3×100 mL). The organic layer was dried over anhydrous sodium sulfate, concentrated under vacuum to obtain the crude product (40 mg) which was purified by reverse phase HPLC to yield (Z)-2,8-Dimethyl-5-(1-methyl-2-phenyl-vinyl)-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (10 mg) and (E)-2,8-Dimethyl-5-(1-methyl-2-phenyl-vinyl)-2,3,4,5-tetrahydro-1H-pyrido[4,3-b]indole (12 mg) which were converted to their respective HCl salts. 1H NMR (CDCl3, free base) δ (ppm): 7.40 (m, 3H), 7.30-7.20 (m, 4H), 6.98 (d, 1H), 6.60 (s, 1H), 3.76 (s, 2H), 2.60 (s, 3H), 2.30 (s, 3H).
