反应详情

Thionyl chloride (6 mL) was addend over 1 min to a 0° C. suspension of 3-bromo-2-methyl benzoic acid (2.15 g, 10 mmol) in DCM (10 mL). After 30 min of stirring, THF (5 mL) was added to induce dissolution. The now homogeneous solution was stirred for 24 h at rt and the volatile component were removed in vacuo. A portion of the crude acid chloride was dissolved in dry isopropyl alcohol (10 mL) and pyridine (2 mL) was added. After stirring for 4 h at rt, the volatile components were removed in vacuo. The residue was partitioned between EtOAc (70 mL) and HCl (1M, 30 mL) and the layers were separated. The organic layer was washed with HCl (1M, 10 mL), NaHCO3 (3×20 mL), water (30 mL), brine (30 mL), and was dried over sodium sulfate. Removal of solvent in vacuo yielded the title compound as a light-yellow oil which was used without further purification. 1H-NMR (CDCl3): δ 7.69 (d, 2H, J=7.7 Hz), 7.11 (t, 1H, J=7.9 Hz), 5.26 (heptet, 1H, J=6.3 Hz), 2.63 (s, 3H), 1.39 (d, 6H, J=6.3 Hz).

1. dissolutiondissolution
2. stirringThe now homogeneous solution was stirred for 24 h at rt
3. customthe volatile component were removed in vacuo
4. dissolutionA portion of the crude acid chloride was dissolved in dry isopropyl alcohol (10 mL)
5. additionpyridine (2 mL) was added
6. stirringAfter stirring for 4 h at rt
7. customthe volatile components were removed in vacuo
8. customThe residue was partitioned between EtOAc (70 mL) and HCl (1M, 30 mL)
9. customthe layers were separated
10. washThe organic layer was washed with HCl (1M, 10 mL), NaHCO3 (3×20 mL), water (30 mL), brine (30 mL)
11. dry with materialwas dried over sodium sulfate
12. customRemoval of solvent in vacuo