Tetrahydrofuran → Ethyl 5-chloro-3-phenylthioindole-2-carboxylate

Participants

Reaction Steps

To a cold (0°), stirred solution of ethyl 5-chloroindole-2-carboxylate (223 mg) in 4.5 mL dry tetrahydrofuran, under argon, was added 0.55 mL of a solution of ethylmagnesium bromide in ether. The resultant mixture was stirred for 30 min then cooled to -78°. Solid S-phenyl benzenethiosulfonate (300 mg) was added and the mixture stirred at -78° for 30 min and 0° for 1 h. The mixture was then diluted with ether and saturated aqueous ammonium chloride added. The organic layer was separated, washed with water and brine and dried over MgSO4. Filtration and concentration gave a yellow oil which was purified by flash chromatography on silica gel. Elution with hexane ethyl acetate (85:15) gave the title product. IR (KBr) 3340, 3060, 2994, 1680, 1508, 1263 and 738 cm-1 ; 1H NMR (250 MHz, CDCl3) 6 1.28 (t, 3H, J =7 Hz), 4.39 (q, 2H, J =7 Hz), 7.08-7.24 (m, 5H), 7.27 (dd, 1H, J =9 and 2 Hz), 7.39 (d, 1H, J =9 Hz), 7.60 (d, 1H, J =2 Hz).

Provenance & Evidence