反应详情

A mixture of 4-bromo-2,6-difluorobenzoic acid (6.7 g, 28.3 mmol), MeOH (200 ml) and concentrated HCl (2.0 ml) was heated at reflux for 12 h. The reaction mixture was brought to ambient temperature and the volatiles were evaporated. EtOAc was added and the organic phase was extracted with a aquous solution of Na2CO3 (10%). The combined alkaline phases was acidified at 0° C. with aqueous HCl (10%) to pH 1 and extracted with EtOAc. The combined organic phases was dried (Na2SO4), filtered and concentrated in vacuo to afford pure title compound (3.1 g). MS m/z (rel. intensity, 70 eV) 252 (M+, 22), 250 (M+, 23), 221 (99), 219 (bp), 112 (44).

1. temperaturewas heated
2. temperatureat reflux for 12 h
3. customwas brought to ambient temperature
4. customthe volatiles were evaporated
5. additionEtOAc was added
6. extractionthe organic phase was extracted with a aquous solution of Na2CO3 (10%)
7. customwas acidified at 0° C. with aqueous HCl (10%) to pH 1
8. extractionextracted with EtOAc
9. dry with materialThe combined organic phases was dried (Na2SO4)
10. filtrationfiltered
11. concentrationconcentrated in vacuo