[Synthesis]
a) A mixture of (RS)-pyrrolidin-2-ylmethanol (1.00 g, 9.90 mmol, 1.0 eq.), 35% aqueous formaldehyde (10 mL) and 10% (1-methylpyrrolidin-2-yl)methanol was reacted with Pd/C (200 mg) for 18 hours with stirring under hydrogen atmosphere. Upon completion of the reaction, the mixture was filtered through a pad of diatomaceous earth and the filtrate was concentrated under reduced pressure and subsequently purified by silica gel column chromatography (eluent: 20% methanol/chloroform) to give a colorless liquid product (650 mg, 56% yield). The product was characterized by 1H NMR (400 MHz, CDCl3): δ 3.65 (dd, J = 10.0, 3.6 Hz, 1H), 3.43 (dd, J = 10.8, 2.0 Hz, 1H), 3.10-3.05 (m, 1H), 2.40-2.35 (m, 1H), 2.33 (s, 3H), 2.32-2.25 (m , 1H), 1.93-1.68 (m, 4H); mass spectrum (APCI+): m/z 116 [M + H]+. |