C(=O)([O-])[O-].[K+].[K+].S([O:12][CH3:13])(OC)(=O)=O.[CH2:14]([O:21][C:22]1[C:31]([CH:32]([CH3:34])[CH3:33])=[CH:30][C:25]([C:26]([O:28][CH3:29])=[O:27])=[C:24](O)[CH:23]=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1>C(#N)C>[CH2:14]([O:21][C:22]1[C:31]([CH:32]([CH3:34])[CH3:33])=[CH:30][C:25]([C:26]([O:28][CH3:29])=[O:27])=[C:24]([O:12][CH3:13])[CH:23]=1)[C:15]1[CH:20]=[CH:19][CH:18]=[CH:17][CH:16]=1Anhydrous potassium carbonate (450 mg, 3.26 mmol) and dimethyl sulphate (0.25 ml, 2.64 mmol) were added to a suspension of methyl 4-benzyloxy-2-hydroxy-5-isopropylbenzoate (650 mg, 2.17 mmol) in acetonitrile (20 ml) and the mixture was stirred and held at reflux for 16 hours. Upon cooling to room temperature the solvent was removed in vacuo and the residue acidified by the addition of 2M hydrochloric acid (20 ml). The organic material was extracted with ethyl acetate (2×30 ml) and the combined organic extracts were evaporated in vacuo to afford methyl 4-benzyloxy-5-isopropyl-2-methoxybenzoate (644 mg, 95%) as a pale yellow solid. 1H NMR (DMSO-d6) 7.56 (1H, s), 7.50 (2H, d), 7.43 (2H, t), 7.37 (1H, t), 6.80 (1H, s), 5.26 (2H, s), 3.83 (3H, s), 3.75 (3H, s), 3.19 (1H, m), 1.17 (6H, d). MS: [M+H]+ 315.
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