反应详情

and (c) A mixture of N-(1-ethylpyrazol-5-yl)-3-bromoanthranilic acid and N-(1-ethylpyrazol-5-yl)-5-bromoanthranilic acid (34.8 g, 0.11 mol) and POCl3 (100 ml) is heated at reflux for 8 hours. The reaction mixture is cooled to room temperature, and then is poured into ice water and neutralized with concentrated NH4OH. The mixture is extracted with CH2Cl2 and the CH2Cl2 layer is dried over MgSO4 and evaporated to dryness. The residue is purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1) to afford 2.7 g of 1-ethyl-4-chloro-8-bromo-1H-pyrazolo[3,4-b]quinoline (labelled as Example 44(b)) and 22.5 g (64%) of 1-ethyl-4-chloro-6-bromo-1H-pyrazolo[3,4-b]quinoline (labelled as Example 44(c)).

1. temperatureis heated
2. temperatureat reflux for 8 hours
3. extractionThe mixture is extracted with CH2Cl2
4. dry with materialthe CH2Cl2 layer is dried over MgSO4
5. customevaporated to dryness
6. customThe residue is purified by column chromatography on silica gel eluting with CH2Cl2 /ether (9/1)