87.85% |
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n-BuLi [(18.6 g, 2.5 eq (2.5M soln) was added to a stirred solution of (3-bromo-4- methylphenyl) methanol (5.5 g, 27.4 mmol) in THE (50 mL) at -78 00 and was stirred at same temperature for 30 mm. Then, 002 gas was purged (generated from dry ice)for about 10 mm. The reaction mixture thus obtained was quenched with ammonium chloride and acidified with 1 N HCI, extracted with ethyl acetate, the organic layer was washed with water, brine solution. Then the reaction mixture was dried over anhydrous Na2SO4 and concentrated under reduced pressure and washed with nhexane to obtain the title compound (4.0 g, 87.85%) as an off white solid. LOMS165.0 (M-H) 1H NMR: (ODd3, 300MHz) 6 12.67 (5, 1H), 7.79 (5, 1H), 7.36-7.38 (d,1 H), 7.23-7.25 (d, 1 H), 5.23 (5, 1 H), 4.49 (5, 2H), 2.50 (5, 3H). |
87.85% |
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To a stirred solution of <strong>[68120-35-4](3-bromo-4-methylphenyl) methanol</strong> (5.5 g, 27.4 mmol) in THF (50 mL) at -78C, n-BuLi [(18.6 g, 2.5 eq (2.5M soln) was added and the solution was stirred at same temperature for 30 mm. Then, 002 gas was purged (generated from dry ice) for about 10 mm. The reaction mixture was quenched with ammonium5 chloride and acidified with 1 N HCI, extracted with ethyl acetate, the organic layer was washed with water, brine solution. Then, it was dried over anhydrous Na2S04 and concentrated under reduced pressure and washed with n-hexane to obtain the title compound (4.0 g, 87.85%) as an off white solid. LCMS : 165.0 (M-H) 1H NMR:(CDCI3, 300MHz) 6 12.67 (5, 1H), 7.79 (5, 1H), 7.36-7.38 (d, 1H), 7.23-7.25 (d, 1H), 10 5.23 (5, 1H), 4.49 (5, 2H), 2.50 (5, 3H). |
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Example 135. S-Hydroxymethyl-I-methyl-benzoic acid (77); [0318] To a solution of compound 76 described in Example 134 (1.8 g, 9.0 mmol) inTHF (20 mL) at -78 C under the argon atmosphere was added slowly n-butyl lithium (2.5 M in hexane; 7.0 mL, 15 mmol). The mixture was stirred at the same temperataure for 30 min and couple pieces of dry-ice pellet added. The temperature was raised to room temperature over 4 h and the reaction quenched with IM HCl carefully and then extracted with ethyl acetate. The mixture was extracted with ethyl acetate and the organic separated. The organic layer was washed with brine, dried over Na2S O4 and filtered. The filtrate was concentrated and the crude product used in the next step without further purification. |