反应详情

A suspension of 4,5-dimethoxy-2-nitrobenzoic acid 1 (2 g; 8.8 mmol) in SOCl2 (10 mL) was stirred under reflux for 50 minutes. After cooling, the reaction mixture was poured into a mixture of concentrated NH4OH (50 mL) and ice (30 g). The precipitate were collected by filtration, washed with water, and dried to give 1.85 g crude crystals. After recrystallization from DMF, 1.76 g pure product was obtained (88.5%). 1H NMR(DMSO-d6): δ 7.60(s, 2H, —NH2), 7.57(s, 1H, 6-H), 7.12(s, 1H, 3-H), 3.90, 3.87(s, s, 6H, —OCH3); IR(Kr) υmax: 3454, 2840, 1670, 1512, 1274, 1227 cm−1; GC/MS m/z 226(M+, 10.0), 178(98.5), 163(100.0), 135(51.0).

1. temperatureunder reflux for 50 minutes
2. temperatureAfter cooling
3. filtrationThe precipitate were collected by filtration
4. washwashed with water
5. customdried
6. customto give 1.85 g crude crystals
7. customAfter recrystallization from DMF