反应详情

Boron tribromide in dichloromethane (1 M, 900 mL, 900 mmol) was added drop wise to a cooled (−30-−40° C.) solution of 4-chloro-2-(2-methoxyphenyl)-7-methylquinazoline (93.2 g, 328 mmol) in dichloromethane (2 L) under nitrogen atmosphere. The resulting mixture was left warming to room temperature in about four hours and was slowly poured in 4 L sat. aq. NaHCO3. Stirring was continued until no more CO2 was produced. The layers were separated and the organic layer was dried over sodium sulfate, filtered, and evaporated to dryness under reduced pressure, yield: 90 g. The residue was filtered over a short plug of silica with dichloromethane as the eluent. Yield: 57.9 g (65%) of 2-(4-chloro-7-methylquinazolin-2-yl)phenol (1H-NMR, LC-MS: >90% purity). It was found that the only impurity still present was the corresponding bromo quinazoline (LC-MS, M+found=271 [M+1]; 315, 317 [M-Cl+Br], Br-isotope patterns present).

1. waitThe resulting mixture was left
2. customwas produced
3. customThe layers were separated
4. dry with materialthe organic layer was dried over sodium sulfate
5. filtrationfiltered
6. customevaporated to dryness under reduced pressure, yield: 90 g
7. filtrationThe residue was filtered over a short plug of silica with dichloromethane as the eluent