反应详情

4-Oxo-3,4-dihydroquinazoline-2-carboxamide (40b, 0.51 g, 2.69 mmol) was heated to 100° C. in POCl3 (7.0 mL) for three hours. The solvent was removed under reduced pressure. Ice-cold water was carefully added to the flask, and the insoluble product was filtered off. The filtrate was extracted three times with chloroform. The combined organics were dried (MgSO4) and evaporated to give 4-Chloroquinazoline-2-carbonitrile (40c, 0.21 g). 95% pure by HPLC and used without further purification. The insoluble product was purified by flash silica gel chromatography eluting with 3-30% EtOAc/hexane to give an additional 0.22 g of 40c as a white solid for an overall yield of 62%. Rf=0.53 (30% EtOAc/hexane). 1H NMR (400 MHz, DMSO-d6): δ 8.07-8.11 (m, 1H), 8.24-8.31 (m, 2H), 8.41 (d, J=8.4 Hz, 1H).

1. customThe solvent was removed under reduced pressure
2. additionIce-cold water was carefully added to the flask
3. filtrationthe insoluble product was filtered off
4. extractionThe filtrate was extracted three times with chloroform
5. dry with materialThe combined organics were dried (MgSO4)
6. customevaporated