Carbon Disulfide → 4-Isopropyl-3-isothiocyanatotoluene

Participants

Reaction Conditions

Reaction Steps

To 2-isopropyl-5-methylaniline (1.0 g, 6.7 mmol) in a 25 mL vial equipped with a stir bar, Vigreux column, and nitrogen was added carbon disulfide (3.0 mL, 50 mmol). The reaction was heated to 40° C. and cooled immediately. To this solution was added triethylamine (0.93 mL, 6.7 mmol). The reaction was heated to 50° C. for 90 minutes and cooled to room temperature overnight. The reaction mixture was transferred to a 100 mL round-bottomed flask and concentrated. The residue was taken up in acetonitrile (33.5 mL) and treated with N,N′-diisopropycarbodiimide (1.04 mL, 6.70 mmol). The reaction was stopped after a few h and concentrated. Purification by flash column chromatography using 2.5-5% ethyl acetate/hexanes as eluent provided a mixture of products. Re-purification by reversed phase column chromatography using 5-100% acetonitrile/water as eluent provided the title compound (65% in dichloromethane, 0.62 g, 31%), which was used without further purification: IR (thin film) 2963 (m), 2924 (m), 2869 (w), 2089 (vs), 1611 (w), 1501 (m) cm−1; 1H NMR (300 MHz, CDCl3) δ 7.16 (d, J=8.6 Hz, 1H), 7.09-7.03 (m, 2H), 3.19 (h, J=6.8 Hz, 1H), 2.30 (s, 3H), 1.24 (d, J=6.9 Hz, 6H); 13C NMR (101 MHz, CDCl3) δ 141.50, 136.70, 134.59, 128.84, 128.58, 127.12, 126.05, 29.20, 22.83, 20.62.

Provenance & Evidence