反应详情

4-Bromo-3-methyl-benzoic acid (2.06 g, 9.6 mmol) and thionyl chloride (2.2 ml, 30.2 mmol) in toluene (50 ml) were heated at reflux for 2 h then concentrated in vacuo and azeotroped with toluene. The residue was dissolved in THF (100 ml) and triethylamine (2.8 ml, 20.1 mmol), cooled down to 0° C. and lithium tert-butoxide (1.24 g, 15.5 mmol) was added portionwise. The mixture was stirred for 18 h at room temperature then concentrated in vacuo. The residue was dissolved in EtOAc, washed with 1M HCl, saturated NaHCO3 then brine, dried and concentrated in vacuo. The residue was purified by flash chromatography on silica gel (eluant; 5% EtOAc:95% pet. ether) to yield the title compound (1.86 g, 71%).

1. temperatureat reflux for 2 h
2. concentrationthen concentrated in vacuo
3. customazeotroped with toluene
4. dissolutionThe residue was dissolved in THF (100 ml)
5. concentrationthen concentrated in vacuo
6. dissolutionThe residue was dissolved in EtOAc
7. washwashed with 1M HCl, saturated NaHCO3
8. dry with materialbrine, dried
9. concentrationconcentrated in vacuo
10. customThe residue was purified by flash chromatography on silica gel (eluant; 5% EtOAc:95% pet. ether)