反应详情

A solution of cyanogen bromide (1.42 g, 13.4 mmol) in anhydrous diethyl ether (10 ml) was added slowly to a stirred solution of 3-(benzylthio)aniline (4.6 g, 21.4 mmol) in anhydrous diethyl ether (25 ml) at 0-4° C. After the addition, the reaction mixture was stirred at room temperature for 12 hours and became a brown solution with a white precipitate. The precipitate was filtered off and the filtrate was washed with aqueous HCl (1 M, 3×40 ml) and followed by brine (40 ml). The ether solution was dried over MgSO4, filtered, and concentrated in vacuo to yield yellow oil as crude product. It was further purified by flash chromatography (SiO2, CH2Cl2/EtOAc, 0-20%) to afford 3-(benzylthio)phenylcyanamide (2.82 g, 55% yield) as a white solid: TLC: Dichloromethane/EtOAc (93:7), Rf=0.64; 1H-NMR (CDCl3) δ (ppm) 7.2-6.7 (m, 9H, Ar—H), 4.12 (s, 2H, S—CH2). IR(KBr): 3178 cm−1 (secondary N—H), 3023-3085 cm−1 (C—H aromatic stretch), 2227 cm−1 (CN).

1. additionAfter the addition
2. filtrationThe precipitate was filtered off
3. washthe filtrate was washed with aqueous HCl (1 M, 3×40 ml)
4. dry with materialThe ether solution was dried over MgSO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customto yield yellow oil as crude product
8. customIt was further purified by flash chromatography (SiO2, CH2Cl2/EtOAc, 0-20%)