m-Chloroperbenzoic acid → 4-(3-Ethanesulphinylpropyl)-2-fluoro-1-triphenylmethylimidazole

Participants

Reaction Steps

A solution of ethanethiol in DMF was treated with sodium hydride, and then with 2-fluoro-4-(3-methanesulphonyloxypropyl)-1-triphenylmethylimidazole. After stirring at ambient temperature for 16 hours, the mixture was worked up by extraction and chromatography to give 4-(3-ethylthiopropyl)-2-fluoro-1-triphenylmethylimidazole, having the following n.m.r. in CDCl3 : 1.2 (t, 3H); 1.85 (quintet, 2H); 2.48 (q, 6H); 6.24 (s, 1H); 7.0-7.4 (m, 15H). This thioether was dissolved in CH2Cl2, cooled to 0°, and treated in portions with one equivalent of 3-chloroperbenzoic acid, having the reaction closely by HPLC. Complete conversion to product occurred 10 minutes after the final addition of peracid. The solution was extracted with aqueous sodium bicarbonate, dried and evaporated to give 4-(3-ethanesulphinylpropyl)-2-fluoro-1-triphenylmethylimidazole, having the following n.m.r. in CDCl3 : 1.28 (t, 3H); 2.02 (quintet, 2H); 2.66 (m, 6H); 6.27 (s, 1H); 7.0-7.4 (m, 15H).

Provenance & Evidence