cis-4-(3,5-Bis-trifluoromethyl-benzylamino)-2-methyl-2,3,4,6,7,8-hexahydro-cyclopenta[g]quinoline-1-carboxylic acid ethyl ester (Example 4) (1.30 g, 2.55 mmol) was dissolved in anhydrous dichloromethane (100 mL), and pyridine (2.05 mL, 25.5 mmol) was added. The mixture was cooled to 0° C., and methyl chloroformate (1.97 mL, 25.5 mmol) was slowly added over 20 min. The reaction was stirred at 0° C. for 1 h, then at room temperature for 18 h. The reaction mixture was then diluted with chloroform, and washed twice with 1N HCl. The organic layer was dried over magnesium sulfate, filtered and concentrated in vacuo. Purification by silica gel chromatography using 10% ethyl acetate/hexanes as eluent afforded the title compound (1.00 g). MS m/z 558 (M+); 1H NMR (CDCl3) δ1.1(d, 3H), 2.9 (m, 4H), 3.8 (s, 3H), 6.8 (s, 1H), 7.3 (s, 1H).
