Dimethyl Sulfate → (E)-methyl 2-[2-(3-hydroxyphenoxy)phenyl]-3-methoxypropenoate

Beteiligte Stoffe

Reaktionsschritte

To a suspension of sodium hydride (0.558 g, 0.023 moles in DMF (20 ml) was added dropwise a solution of methyl 2-(3-hydroxyphenoxy)phenylacetate (D) (2.0 g; 0.0077 mol) in DMF (10 ml) and methylformate (10 g; 0.167 mol) After stirring for 45 minutes, water (100 mls) was added and the mixture was extracted with ether (50 mls). The aqueous layer was acidified with hydrochloric acid to pH 3-4 and the mixture was extracted with ether (2×40 mls). The combined ether extracts were washed with water (3×30 mls) and saturated brine (1×30 ml), and then dried. The ether was evaporated off and the residue was dissolved in DMF (20 ml), and anhydrous potassium carbonate. (0.64 g; 0.0046 moles) and dimethyl sulphate (0.55 g; 0.0044 moles) was added. The mixture was stirred at ambient temperature for 1 hour, then water (100 ml) was added, and the mixture was extracted with ether (2×40 ml). The combined ether extracts were washed with water (3×20 ml) and saturated brine (20 ml), dried, filtered, evaporate to dryness, then chromatographed using a mixture of ether and hexane as eluant to give (E)-methyl 2-[2-(3-hydroxyphenoxy)phenyl]-3-methoxypropenoate (E) as an amber gum which, on trituration with a mixture of hexane and dichloromethane, gave a white solid, [0.7 g, 30% yield from methyl 2-(3-hydroxyphenoxy)phenylacetate (D)] m.p. 115°-116° C.

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