methyl 2-bromo-4-chloro-5-methoxybenzoate

反応条件: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

実験手順: To a solution of methyl 2-bromo-4-chloro-5-methoxybenzoate (1.88 g, 6.7 mmol, Powers, J. J.; Favor, D. A.; Jeganathan, A.; Rankin, T.; Sharma, R.; Pandit, C.; Maiti, S, N. Tetrahedron Lett. 2009, 50(12), 1267-1269) in anhydrous THF (20 mL) was added lithium borohydride (0.644 g, 30 mmol). The resulting mixture was heated under reflux for about 72 h. After cooling to rt the mixture was concentrated in vacuo. The residue was partitioned between water (50 mL) and ethyl acetate (90 mL). The layers were separated and the aqueous layer was extracted with ethyl acetate (50 mL). The combined organic layers were washed with water (20 mL), dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by column chromatography (SiO2, diethyl ether/hexanes 1:1) to give (2-bromo-4-chloro-5-methoxy-phenyl)methanol (1.57 g, 6.3 mmol, 93%) as a white solid: 1H-NMR (CDCl3, Bruker 400 MHz) δ 2.01 (1 H, t, J=6 Hz), 3.92 (3 H, s), 4.71 (2 H, d, J=6 Hz), 7.12 (1 H, s), 7.53 (1 H, s). The resulting mixture was heated under reflux for about 72 h was concentrated in vacuo The residue was partitioned between water (50 mL) and ethyl acetate (90 mL) The layers were separated the aqueous layer was extracted with ethyl acetate (50 mL) The combined organic layers were washed with water (20 mL) dried (MgSO4) filtered concentrated in vacuo The residue was purified by column chromatography (SiO2, diethyl ether/hexanes 1:1)