4-Chlorophenyl Isocyanate → 3,5-dichloro-N-[(4-chlorophenylamino)carbonyl]-4-pyridinecarboxamide

Participants

Reaction Steps

A reaction vessel was charged with sixty-eight grams (0.36 mole) of 3,5-dichloro-4-pyridinecarboxamide, 55.5 grams (0.36 mole) of p-chlorophenyl isocyanate, and 1200 milliliters of xylene. The solution was heated under reflux with stirring for three hours. A small amount of impurity was removed by filtering the hot reaction mixture. On cooling in an ice water bath, a solid precipitated. The precipitated product was collected by suction filtration, washed with cold xylene and dried in a vacuum oven at about 70° C. The dried crude product was purified by recrystallization from 90 percent aqueous acetic acid. The yield was 81 grams (66 percent of theoretical) of white needles melting at 225°-227° C. Nuclear magnetic resonance spectral data confirmed the structure as being ##STR12##

Provenance & Evidence