反应详情

A suspension of N-(2-amino-4,5-dichlorophenyl)-2-ethoxy-4-cyanobenzamide (19 g, 54.2 mmol) and P2O5 (19 g, 134 mmol) in xylene (380 ml) was refluxed for 24 h. Additional P2O5 (9.5 g, 67 mmol) was added and the mixture was refluxed for 48 h. Solvent was removed under reduced pressure. The residue was treated with 30% NaOH (80 ml) and water (100 ml) and then acidified with 37% HCl. The solid was filtered, washed with water and dried under vacuum at 50° C. to give 16.5 g of the title compound as a light brown powder (yield 82.6%), mp>250° C.

1. temperaturewas refluxed for 24 h
2. temperaturethe mixture was refluxed for 48 h
3. customSolvent was removed under reduced pressure
4. additionThe residue was treated with 30% NaOH (80 ml) and water (100 ml)
5. filtrationThe solid was filtered
6. washwashed with water
7. customdried under vacuum at 50° C.