反应详情

A solution of chlorine (1.5 g) in carbon tetrachloride (42 ml) was added in portions in a stirred partial solution of benzaldehyde oxime [2.5 g; 1H NMR: δ8.18 (1H, s), 9.40 (1H, brs) ppm] in carbon tetrachloride (20 ml) at room temperature. Following the addition, the reaction mixture was stirred at room temperature for 3 hours then poured into water. The organic layer was separated, dried and concentrated to give almost pure α-chlorobenzaldehyde oxime (3.2 g) as a yellow liquid. A solution of sodium methanethiolate (0.68 g) in methanol (15 ml) was added dropwise to an ice-cooled and stirred solution of part of this α-chlorobenzaldehyde oxime (1.5 g) in methanol (15 ml). Following the addition, the reaction mixture was stirred for 2 hours with continued cooling in iced-water. The methanol was removed under reduced pressure and the residue was chromatographed using dichloromethane as eluant to give a single stereoisomer of α-methylthiobenzaldehyde oxime (0.67 g, 42% yield) as a white crystalline solid, m.p. 76°-78° C., 1H, NMR: δ2.08 (3H, s), 9.12 (1H, s) ppm.

1. additionthe addition
2. customThe organic layer was separated
3. customdried
4. concentrationconcentrated