Carbon Disulfide → Propanoic acid, 2-methyl-2-[(phenylthioxomethyl)thio]-, ethyl ester

Participants

Reaction Conditions

Reaction Steps

Phenyl magnesium bromide was prepared from bromobenzene (6.28 g, 0.04 mol) and magnesium turnings (1 g) in dry THF (30 mL). The solution was warmed to 40° C. and carbon disulfide (3.05 g, 0.04 mol) was added over 15 minutes while maintaining the reaction temperature at 40° C. To the resultant dark brown solution was added ethyl a-bromoisobutyrate (7 g, 0.036 mol). The reaction temperature was raised to 80° C. and maintained for 60 hours. Ice water (50 mL) was added and the organic products were extracted with diethyl ether (3×50 mL). The combined organic extracts were washed with water, brine and dried over anhydrous magnesium sulfate. After removal of solvent and purification by column chromatography (Kieselgel-60, 70-230 mesh, n-hexane/diethyl ether (9:1) eluent), 2-(ethoxycarbonyl)prop-2-yl dithiobenzoate was obtained as a red oil (4.52 g, 42.2% yield). 1H-nmr (CDCl3) d (ppm): 1.25 (t, 3H, CH2CH3), 1.77 (s, 6H, 2×CH3), 4.17 (q, 2H, OCH2CH3), 7.35 (dd, 2H, meta-ArH), 7.52 (dd, 1H, para-ArH) and 7.95 (d, 2H, ortho-ArH).

Provenance & Evidence