Acetyl chloride → Benzoic acid, 3-methoxy-4-methyl-, methyl ester

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Reaction Steps

A solution of 3-methoxy-4-methylbenzoic acid (6.0 g) in methanol (120 ml) was treated with acetyl chloride (6 ml) and stirred for 36 hours. The solution was evaporated. The residue was dissolved in methanol (100 ml) and the solution evaporated. This procedure was repeated to give methyl 3-methoxy-4-methylbenzoate as a colorless oil (6.34 g, 98%); NMR: 2.2(s, 3H, CH3), 3.9(2s, 6H, 2xOCH3), 7.1(d, 1H), 7.5(m, 2H). A solution of ester prepared according to the method described above (121.2 g) in carbon tetrachloride (1400 ml) was heated under gentle reflux with a 350 watt tungsten lamp and subjected to an air purge by means of a T-tube attached to a water aspirator. A solution of bromine (107.2 g) in carbon tetrachloride (500 ml) was added dropwise over 4 hours. Evaporation of the solvent gave a light yellow solid which was triturated with a solution (500 ml) of 1:9 (v/v) ether:hexane. The solid was collected by filtration to give methyl 4-bromomethyl-3-methoxybenzoate (111.7 g, 64%) as a light yellow solid; mp 87°-90° C.; NMR: 3.9(2s, 6H, 2xOCH3), 4.5(s, 2H, BrCH2), 7.4(m, 3H).

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