Dimethyl Disulfide → tert-butyl 1-(4-chlorophenyl)-2-(2,4-dichlorophenyl)-5-methylsulfanyl-1H-imidazole-4-carboxylate

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Reaction Steps

To a cooled (−20° C.) and magnetically stirred solution of tert-butyl 1-(4-chlorophenyl)-2-(2,4-dichlorophenyl)-1H-imidazole-4-carboxylate (10.59 g, 25.0 mmol), in anhydrous THF (100 ml) was added LDA (15.0 ml, 2 M solution in heptane/THF, 30.0 mmol) and the resulting mixture was stirred for 1 hour under N2. A solution of (CH3S)2 (2.7 ml, 30.0 mmol) in THF (20 ml) was added and the resulting solution was successively stirred at −40° C. for 1 h, allowed to attain room temperature and stirred for another 16 h. A saturated aqueous NH4Cl solution (250 ml) was added and the resulting solution was extracted twice with ethyl acetate (EtOAc). The combined organic layers were washed with water, dried over MgSO4, filtered and concentrated to give tert-butyl 1-(4-chlorophenyl)-2-(2,4-dichlorophenyl)-5-methylsulfanyl-1H-imidazole-4-carboxylate in 90% yield as an oil which slowly solidified; 1H-NMR (200 MHz, CDCl3) δ 1.66 (s, 9H), 2.28 (s, 3H), 7.05 (br d, J˜8 Hz, 2H), 7.25 (dd, J=8 and 2 Hz, 1H), 7.28 (d, J=2 Hz, 1H), 7.32–7.41 (m, 3H).

Provenance & Evidence