反应详情

A mixture of 7-chloro-6-nitro-3,4-dihydroquinazolin-4-one (40 g, 0.18 mol), (J. Org. Chem. 1975, 40, 356), phosphorus oxychloride (50 ml) and DMF (1 ml) in thionyl chloride (300 ml) was heated at reflux for 4 hours. The reaction mixture was allowed to cool and the volatiles removed by evaporation and by azeotroping with toluene. The residue was basified with aqueous sodium hydrogen carbonate solution and extracted with methylene chloride (4×100 ml). The extracts were combined, washed with brine and filtered through phase separating paper. The solvent was removed by evaporation and the residue triturated with ether/isohexane to give 4,7-dichloro-6-nitroquinazoline (35.2 g, 81%) as a pale yellow solid.

1. temperaturewas heated
2. temperatureat reflux for 4 hours
3. temperatureto cool
4. customthe volatiles removed by evaporation
5. customby azeotroping with toluene
6. extractionextracted with methylene chloride (4×100 ml)
7. washwashed with brine
8. filtrationfiltered through phase
9. customseparating paper
10. customThe solvent was removed by evaporation
11. customthe residue triturated with ether/isohexane