反应详情

A vigorously stirred mixture of 2-methylphenyl-cyanamide [1.107 g, 0.380 mmol, prepared from o-toluidine by the method of Safter et al. (1948)] and 2-methyl-4-nitroaniline hydrochloride in chlorobenzene (45 ml) was heated at 90° for 3 h and then allowed to cool to 25°. The resulting pale yellow precipitate was collected, washed with CH2Cl2, and dried, giving 2.284 g (91%) of the hydrochloride of the desired product (pure by NMR). A 681 mg sample was recrystallized twice from absolute EtOH to give 600 mg (88%) of the desired product as pale yellow microcrystals suitable for the next reaction: mp 196-200; (CD3OD, 300 MHz) 2.37 (s, 3), 2.47 (s, 3), 7.33-7.40 (m, 4), 7.59 (d, 1), 8.18 (dd, 1), 8.27 (d, 1). A 473 mg sample of the hydrochloride was dissolved in 50 ml of hot water, filtered, cooled to 25°, and treated with 5 ml of 5 N NaOH. The resulting bright yellow precipitate of the title compound (free base) was dried (403 mg, 92%) and then recrystallized twice from 95% EtOH to give the analytical sample as yellow platelets: mp 177-179; (DC3OD, 300 MHz) 2.31 (s, 6), 7.01-7.35 (m, 5), 7.98 (dd, 1), 8.06 (d, 1). Analysis calculated for C15H16N4O2 :C, 63.37; H, 5.67; N, 19.71. Found: C, 63.41; H, 5.42; N, 19.90.

1. temperaturewas heated at 90° for 3 h
2. temperatureto cool to 25°
3. customThe resulting pale yellow precipitate was collected
4. washwashed with CH2Cl2
5. customdried