4-Fluorophenyl isocyanate → HCID 10291483, compound

Participants

Reaction Steps

A slurry of N-methyl-3-amino-5-tert-butylthiophene-2carboxamide (7.63 g, 36 mmol) and 4-fluorophenyl isocyanate (4.93 g, 36 mmol, 1.0 equiv) in anh. toluene (100 mL) was heated at the reflux temp. for 3 h, during which the mixture clarified then generated a new precipitate, which was filtered while hot. The resulting solids were washed with hexane and dried under reduced pressure to afford N-(2-methylcarbamoyl-5-tert-butylthienyl)-N′-(4-fluorophenyl)urea (10.2 g, 81%): mp 203-4° C.; TLC (5% MeOH/CH2Cl2) Rf0.61; 1H NMR (CDCl3) δ1.34 (s, 9H), 2.73 (d, J=4.4 Hz, 3H), 7.07-7.13 (m, 2H), 7.49-7.54 (m, 2H), 7.80 (s, 1H), 7.96 (q, J=4.4 Hz, 1H), 9.88 (s, 1H), 10.46 (s, 1H); 13C NMR (CDCl3) δ25.8, 31.6 (3C), 34.5, 107.4, 115.2 (d, JC-F=22.0 Hz, 2C), 117.3, 120.1 (d, JC-F=7.3 Hz, 2C), 136.1 (d, JC-F=2.4 Hz, 2C), 143.1, 151.6, 157.4 (d, JC-F=238.1 Hz, 1C), 158.0, 164.3; EI-LRMS m/z (rel abundance) 349 (M+, 13%).

Provenance & Evidence