Carbon Disulfide → 5-Phenyl-2(3H)-benzoxazolethione

Participants

Reaction Steps

Carbon disulfide (7.7 mL) was added to a mixture of 2-amino-4-phenylphenol (1.0 g, 5.4 mmol), potassium hydroxide (0.36 g, 6.5 mmol) and ethanol (11.7 mL). The flask was fitted with a reflux condenser and the resulting mixture was placed in an oil bath at 60° C. for 16 h. After cooling to RT, the mixture was concentrated and ethyl acetate (20 mL) and 1 M hydrochloric acid (10 mL) were added to the residue. The layers were partitioned and the organic layer was washed successively with 1 M HCl, water and brine. The organic layer was dried (Na2SO4), filtered and concentrated to afford 1.20 g (98%) which was used without further purification: 1H NMR (d6-DMSO, 400 MHz) δ 13.98 (s, 1H), 7.64-7.62 (m, 2H), 7.58-7.49 (m, 2H), 7.46-7.42 (m, 2H), 7.39-7.33 (m, 2H); 13C (d6-DMSO, 400 MHz) δ 181.2, 148.2, 140.1, 138.5, 132.7, 129.7, 128.3, 127.7, 123.4, 111.0, 109.1; MS (Cl) m/z 228.1 (M+1); HPLC retention time=3.09 min.

Provenance & Evidence