Sulfuric Acid → 1-(5-Chloro-2-methoxyphenyl)-1,3-dihydro-2H-imidazol-2-one

Participants

Reaction Steps

N-(5-Chloro-2-methoxyphenyl)-N′-(2-oxo-2-phenylethyl) urea (4 g, 12.7 mmol) was added to cold (0° C.) concentrated sulfuric acid and stirred for 3 h. The reaction mixture was poured into ice water (2 vol), and extracted with ethyl acetate, washed with saturated NaHCO3 solution and brine before drying over MgSO4. Recrystallization from diethylether/acetonitrile gave 1.35 g (36%). mp 133-134° C.; IR(KBr, υ=cm−1) 2962, 1628, 1576, 1236, 1144, 1130; 1H NMR (300 MHz, CDCl3) δ 3.90 (3H, s), 6.77 (1H, d, J=8.6 Hz), 6.91 (1H, dd, J=8.6 Hz, 2.5 Hz), 7.16 (1H, s), 7.22-7.27 (1H, m), 7.35-7.40 (2H, m), 7.51-7.55 (3H, m), 8.29 (1H, d, J=2.5 Hz); MS(DCl)m/z: 301 (MH+); Anal. calcd. for C16H13ClN2O2: C, 63.90; H, 4.36; N, 9.31. Found: C, 63.66; H, 4.30; N, 9.21.

Provenance & Evidence