Dimethylformamide → 4,7-Dichloro-6-nitroquinazoline

Beteiligte Stoffe

Reaktionsschritte

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.

Herkunft & Nachweise