Dimethyl Carbonate → Methyl 3-(4-cyanophenyl)-3-oxopropanoate

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Reaction Steps

Dimethyl carbonate (126 g, 1.4 moles) was added dropwise to a slurry of NaH (50% in mineral oil, 13.44 g, 0.28 mole) slurried in 280 ml of dry dioxane. The reaction mixture was warmed to 80°-85° and p-cyanoacetophenone (40.7 g, 0.28 mole) in 140 ml dioxane added dropwise (at about 3/4 addition, mechanical loss due to foaming occurred; such losses are avoided by slower addition, e.g., over 1 hour). After addition was complete, heating at 80° was continued for 2 hours and crude product recovered by hot filtration. The cake was distributed between dilute CH3CO2H and ether. The ether layer was separated; washed in sequence with H2O, saturated NaHCO3, H2O and brine; dried; and stripped to yield title product: 39 g, (68.6%); m.p. 93°-98°; tlc (4:1 toluene:ethyl acetate) Rf 0.58. Recrystallization of 0.5 g from 2-propanol gave 0.403 g; m.p. 96°-99°.

Provenance & Evidence