Synlett 2009(17): 2773-2776  
DOI: 10.1055/s-0029-1217989
LETTER
© Georg Thieme Verlag Stuttgart ˙ New York

A Novel, Practical Synthesis of Sulfonyl Chlorides from Thiol and Disulfide Derivatives

Kiumars Bahrami*a,b, Mohammad Mehdi Khodaei*a,b, Mehdi Soheilizada
a Department of Chemistry, Razi University, Kermanshah 67149, Iran
Fax: +98(831)4274559; e-Mail: kbahrami2@hotmail.com; e-Mail: mmkhoda@razi.ac.ir;
b Nanoscience and Nanotechnology Research Center (NNRC), Razi University, Kermanshah, 67149 Iran
Further Information

Publication History

Received 24 July 2009
Publication Date:
24 September 2009 (online)

Abstract

Hydrogen peroxide, in the presence of zirconium tetrachloride, is a very efficient reagent for the direct oxidative conversion of thiol and disulfide derivatives into the corresponding sulfonyl chlorides with high purity through oxidative chlorination. Excellent yields, very short reaction times, mild reaction conditions, and the avoidance of harsh reagents are the main advantages of this method.

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Zirconium tetrachloride, hydrogen peroxide (30%) as well as all the thiol derivatives employed as substrates are commercial products (Merck chemical company) and were used without further purification. Disulfides were prepared according to our previously reported procedure.¹4Melting points were determined in a capillary tube and are uncorrected. ¹H NMR and ¹³C NMR spectra were recorded on a Bruker-200 NMR spectrometer using TMS as internal standard. The concentration of the commercial 30% H2O2 solution was checked iodometrically prior to use. Synthesis of Sulfonyl Chlorides; General Procedure: A mixture of thiol (1 mmol), 30% H2O2 (3 mmol, 0.3 mL) and ZrCl4 (1 mmol, 0.233 g) was stirred in MeCN (5 mL) at 25 ˚C for the appropriate time. After completion of the reaction as indicated by TLC, the reaction mixture was quenched by adding H2O (10 mL), and extracted with EtOAc (4 × 5 mL). The extract was dried with anhydrous MgSO4 and the filtrate was evaporated under vacuum to afford the analytically pure product (Table  [²] ). An identical procedure was employed using 30% H2O2 (2 mmol, 0.2 mL) and ZrCl4 (1 mmol, 0.233 g) for the oxidative chlorination of disulfides (Table  [³] ). All of the products are known compounds and were easily characterized by comparison with authentic samples (¹H NMR, ¹³C NMR, mp).