Reaction Steps
3-Phenyl-3-cyclohexanecarbonyl-butan-1-al (57.8 g, 224 mmol) was dissolved in methylene chloride (1650 mL) followed by addition of 1-(2-methoxyphenyl)piperazine hydrochloride (56.3 g, 246 mmol). Acetic acid (41 mL) may optionally be added to turn the slurry into a solution. To the stirred solution, sodium triacetoxyborohydride (60.3 g, 284 mmol) was slowly added. A slight exotherm resulted and a slurry was produced. The reaction mixture was stirred for an additional 3 hours at room temperature. The reaction was then quenched by addition of 2.0 N sodium hydroxide (1050 mL) producing a pH of about 10 for the quenched reaction mixture. The mixture was then extracted with methylene chloride (2 times, 1L and 300 mL). The organic extracts were combined, washed successively with 1.0 N HCl (600 mL), 1.0 N sodium hydroxide (600 mL), brine (600 mL), dried over anhydrous magnesium sulfate, filtered and concentrated under vacuum to provide the final title compound as a thick oil; UV (MeOH): λmax=243 nm, ε243=7110; λmax=281 nm, ε281=3200; IR (CDCl3, cm−1) 2937, 2856, 2836, 1698, 1499, 1451, 1377, 1316, 1242, 1029; 1H NMR (300 MHz, DMSO) δ 7.75 (2H, m), 7.55 (2H, m), 6.93 (3H, m), 6.85 (2H, m), 3.75 (3H, s), 2.90 (4H, m), 2.43 (4H, m), 2.08 (5H, m), 1.5 (10H, m), 1.05 (3H, m); 13C NMR (300 MHz, DMSO) δ 214.18, 151.94, 141.25, 141.23, 128.45, 126.85, 126.74, 122.22, 120.79, 117.81, 111.97, 55.28, 54.54, 53.67, 53.13, 50.01, 45.30, 33.75, 30.44, 30.12, 25.21, 24.98, 24.93, 19.94. Anal. Calcd for C28H38N2O2: C, 77.38; H, 8.81; N, 6.45. Found: C, 76.44; H, 8.89; N, 6.01.
