反应详情

The title compound was prepared in the same way as that method described for preparing the (S)-enantiomer (M. Lemaire, F. Posada, J.-G. Gourcy and G. Jeminet, Synlett, 1995, 627). A solution of (S)-(2,2-dimethyl-1,3-dioxolan-4-yl)methyl methanesulfonate (3.0 g, 14.27 mmol) and benzylamine (6.23 ml, 57.1 mmol) were refluxed together in CH3CN (38 ml) for 48 h. Tlc (EtOAc-hex 8:2) showed a new product (uv/molybdate or ninhydrin) with Rf ˜0.3 together with a little higher running sm. The solvent was evaporated and the residue dissolved in EtOAc and washed with aqueous sat. NaHCO3, dried and the solvent evaporated. The residue was chromatographed (EtOAc-hex, 6:4 then 8:2) to give (R)—N-benzyl-1-(2,2-dimethyl-1,3-dioxolan-4-yl)methanamine (2.56 g, 11.57 mmol, 81% yield) as a yellow oil. [α]D21 −3.7 (c, 0.885, CHCl3). 1H NMR (CDCl3, 300 MHz), δ ppm, 7.32-7.20 (m, 5H), 4.25, (m, 1H), 4.03 (dd, 1H, J 8.0, 6.4 Hz), 3.82 (s, 2H), 3.68 (dd, 1H, J 8.0, 6.8 Hz), 2.74 (d, 2H, J 5.7 Hz), 1.40 (s, 3H), 1.35 (s, 3H). 13C NMR (CDCl3, 75.5 MHz), δ ppm, 140.6, 128.8, 128.4, 127.3, 109.5, 75.8, 67.9, 54.4, 52.1, 27.3, 25.8.

1. customThe title compound was prepared in the same way as that method
2. customdescribed for preparing the (S)-enantiomer (M. Lemaire, F. Posada, J.-G. Gourcy and G. Jeminet, Synlett, 1995, 627)
3. customThe solvent was evaporated
4. dissolutionthe residue dissolved in EtOAc
5. washwashed with aqueous sat. NaHCO3
6. customdried
7. customthe solvent evaporated
8. customThe residue was chromatographed (EtOAc-hex, 6:4