Toluene → Ethyl α-hydroxy-6-(methoxymethoxy)-7-methyl-1,3-benzodioxole-4-acetate

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Reaction Steps

Into a clean and dry 2 L, 4-necked RB flask was charged 400 ml of N,N-dimethylformamide under nitrogen atmosphere at RT. Cesium carbonate (171 g) was added to the reaction mass under stirring at room temperature. Bromochloromethane (226 g) was added to the reaction mass under stirring at RT. Reaction mass was heated to 30-35° C. Ethyl 2-(2,3-dihydroxy-5-(methoxymethoxy)-4-methylphenyl)-2-hydroxyacetate (50 g) was dissolved in 100 ml of DMF and slowly added to the reaction mass under stirring at 30-35° C. Reaction mass was maintained at 30-35° C. for 2.5 h under stirring. Reaction mass was poured into 1 L toluene and stirred for 1.0 h at RT. Reaction mass was filtered through hyflow bed, and the bed washed with 600 mL of toluene. Filtrate was washed with 2.0 L of DM water. Aqueous layer was extracted with 2×500 mL of toluene. Combined organic layer was washed with 2×600 mL of saturated sodium chloride solution and treated with 7.5 g of activated carbon at 45-50° C. Reaction mass was filtered and distilled of solvent under vacuum at 45-55° C. to get 40 g of crude title compound as syrup. HPLC purity of the crude compound is 92.5%. The crude compound was directly used in next step. A small sample was purified by column chromatography to compare its spectral data with the literature values.

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