Formaldehyde → (+)-3-(2,3-Difluorophenyl)-1-methylpyrrolidin-3-OL

Participants

Reaction Steps

Preparation according to Example 11: Enantiomer E1 of 3-(2,3-difluorophenyl)-pyrrolidin-3-ol (0.15 g, 0.72 mmol), formic acid (1.95 mL), aqueous formaldehyde (40%, 2.17 mL). The mixture was stirred for 5 h after which additional aqueous formaldehyde (1.5 mL) was added and the mixture was refluxed overnight. Purification by flash chromatography on silica gel (ethyl acetate/methanol, 10:1). Yield: 0.09 g. [α]D=+19.1°; The amine was converted to the oxalic acid salt and recrystallized from ethanol/diethyl ether/diisopropyl ether; M.p. 131-132° C.; MS m/z (relative intensity, 70 eV) 213 (M+, 15), 57 (bp), 58 (28), 141 (15), 127 (10), 113 (10).

Provenance & Evidence