反应详情

An aqueous solution of NaHSO3 (21.0 mL, 40% in water) was treated benzaldehyde (2.00 mL, 20.0 mmol) and stirred at ambient temperature for 1 h. A solution of methyl 3,4-diaminobenzoate (3.32 g, 20.0 mmol) in ethanol (15.0 mL) was added and the solution was heated to reflux for 6 h. Upon cooling, the solution was poured into water and the resultant precipitate was collected by filtration, washed with water, and dried in vacuo to provide the title compound as a grey solid (4.90 g; 97%). 1H NMR (400 MHz, CHLOROFORM-d) δ ppm 10.85 (br. s., 1H) 8.35 (s, 1H) 8.11 (d, J=2.0 Hz, 1H) 8.10 (d, J=4.0 Hz, 1H) 7.97 (dd, J=8.6, 1.5 Hz, 1H) 7.63 (d, J=5.8 Hz, 1H) 7.46 (d, J=2.3 Hz, 2H) 7.45 (dd, J=5.5, 4.0 Hz, 1H) 3.94 (s, 3H). MS (ES+) m/e 253 [M+H]+.

1. temperaturethe solution was heated
2. temperatureto reflux for 6 h
3. temperatureUpon cooling
4. filtrationthe resultant precipitate was collected by filtration
5. washwashed with water
6. customdried in vacuo