C. Synthesis of 4-(4-morpholinyl)benzyl alcohol. At -10 °C, 4-(4-morpholinyl)benzoic acid (1.00 g, 4.83 mmol) and 4-methylmorpholine (0.53 mL, 4.8 mmol) were dissolved in tetrahydrofuran (25 mL), followed by the addition of ethyl chloroformate (0.46 mL, 4.8 mmol). After 0.25 h of reaction, sodium borohydride (550 mg, 14.5 mmol) was added to the mixture followed by slow addition of methanol (50 mL). Next, the mixture was treated with 5% aqueous acetic acid, after which the mixture was concentrated. The residue was purified by silica gel column chromatography (eluent: ethyl acetate/hexane) to give 164 mg (18% yield) of 4-morpholinobenzyl alcohol. The product was characterized by 1H NMR, IR spectroscopy, field desorption mass spectrometry (FD-MS, m/e 193 (M+)), and elemental analysis (calculated values for C11H15NO2: C, 68.37; H, 7.82; N, 7.25; measured values: C, 68.46; H, 7.95; N, 7.21).
