Synlett 2005(3): 535-537  
DOI: 10.1055/s-2005-862352
LETTER
© Georg Thieme Verlag Stuttgart · New York

A Mild and Convenient Procedure for Desulfinylation of p-Toluenesulfinyl Amines

Bin Feng Li, Ke Yuan, Li Xin Dai, Xue Long Hou*
State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 354 Fenglin Lu, Shanghai 200032, P. R. China
e-Mail: xlhou@mail.sioc.ac.cn;
Further Information

Publication History

Received 12 November 2004
Publication Date:
17 January 2005 (online)

Abstract

Reaction of p-toluenesulfinyl amines with thiophenol in the presence of catalytic amount of ZnCl2 provides the corresponding desulfinylated amines in high yield.

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General Procedure for Desulfinylation. Under argon atmosphere, p-toluenesulfinyl amine (1 mmol) was dissolved in CH2Cl2 (4 mL). Anhyd ZnCl2 (0.1 mmol) and PhSH (3 mmol) were added, the reaction mixture was stirred at r.t. and monitored by TLC. After completion, the reaction mixture was quenched by addition of sat. NH4Cl solution (10 mL). The aqueous phase was extracted with CH2Cl2 (3 × 10 mL), and the combined organic layers were dried over Na2SO4, concentrated, and purified by column chromatography over silica gel to give the product.
1-(4-Chlorophenyl)but-3-en-1-amine ( 2f): 1H NMR (CDCl3/TMS, 300 MHz): δ (ppm): 2.32-2.43 (m, 2 H), 3.99 (dd, J = 7.9, 5.5 Hz, 1 H), 5.07-5.14 (m, 2 H), 5.71-5.73 (m, 1 H), 7.18-7.39 (m, 4 H).
(2 R ,3 S )-2-Amino-3-(benzylamino)-4-[(4-chloro-phenyl)thio]butanenitrile ( 2g): 1H NMR (400 MHz, CDCl3-D2O): δ = 2.93-2.98 (m, 1 H), 3.03 (dd, J 1 = 13.6 Hz, J 2 = 6.0 Hz, 1 H), 2.97-3.02 (m, 1 H), 3.18 (dd, J 1 = 13.6 Hz, J 2 = 6.7 Hz, 1 H), 3.85, 3.89 (AB, J = 13.4 Hz, 2 H), 3.93 (d, J = 3.8 Hz, 1 H), 7.20-7.33 (m, 9 H). [α]D 20 +39.2 (c 1.12, CHCl3). IR (neat): 3385, 3324, 2231 cm-1. MS (EI): m/z (%) = 32 (16) [M + 1], 276 (60), 91 (100). Anal. Calcd for C17H18ClN3S: C, 61.53; H, 5.47; N, 12.66. Found: C, 61.27; H, 5.68; N, 12.51.

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The ee value of product 2d determined by HPLC was the same as that of α-methylbenzylamine used as starting material to prepare p-toluenesulfinyl amine (1d).