反应详情

温度

100 °C

To methyl 3-bromo-5-carbamoyl-benzoate (2.8 g, 10.8 mmol, 1.0 eq) was added POCl3 (30 mL) and the reaction heated at 100° C. overnight. The POCl3 was removed under reduced pressure, water was added and the aqueous layer extracted with EtOAc. The combined organic extracts were dried (Na2SO4), filtered and evaporated in vacuo to afford a crude residue which was purified by column chromatography (petroleum ether:EtOAc, 20:1) to give methyl 3-bromo-5-cyano-benzoate (2.5 g, 96%). This material was dissolved in THF (30 mL) and LiOH.H2O (1.7 g, 41.6 mmol, 1.54 eq) and H2O (10 mL) were added. The mixture was stirred at room temperature overnight. The THF was removed under reduced pressure and the aqueous phase acidified with diluted HCl and extracted with EtOAc. The combined organic extracts were dried (Na2SO4), filtered and evaporated in vacuo. The residue obtained was purified by column chromatography (CH2Cl2: MeOH, 50:1) to give the title compound as a white solid (2 g, 85%).

1. customThe POCl3 was removed under reduced pressure, water
2. additionwas added
3. extractionthe aqueous layer extracted with EtOAc
4. dry with materialThe combined organic extracts were dried (Na2SO4)
5. filtrationfiltered
6. customevaporated in vacuo
7. customto afford a crude residue which
8. customwas purified by column chromatography (petroleum ether:EtOAc, 20:1)