Preparation of α-cyanoacrylate from Methylacrylate

Abstract

Methyl acrylate is cony erted quantitatively to methyl α, β-dichloropropionate by chlorination at room temperature in the presence of 4 mol-% DMF as the catalyst.Methyl α, β-dichloropropionate is then methoxylated by reaction with an equimolar amount of Na-methylate in one hour without a catalyst at -20 to -35°C in mately 90% yield.Methyl α-chloro-β-methoxypropionate is let to react with an equimolar amount of potassiumcyanide at 30°C in a homogeneous solution. The yield is about 95%, but part of the produced α-cyano-β-methoxy propionate changes into poly-α-cyanoacrylate. Therefore, the true cyanation yield appears to be between 60 to 70%.Then crude methyl α-cyano-β-methoxypropionate is converted to methyl α-cyanoacrylate at rather high temperature, since the reaction involves the degradation of poly-α-cyanoacrylate. The reaction is carried out at 170250°C/39mmHg in a SO2 stream in the presence of 3 mole-% sulfuric acid and 100 g of DOP. Approximately 80% yield is attained.