Potassium cyanacetate

Potassium Cyanacetate.—With this Moore 5 obtained at the positive pole carbon dioxide, besides traces of nitrogen and ethylene cyanide at the negative pole hydrogen and potassium hydroxide, bodies analogous to those obtained in the decomposition of sodium acetate. 

Cyanacetic ester. Ethyl chloroacetate is dissolved in ethanol and boiled under reflux, with an alcoholic solution of potassium cyanide. The mixture is then filtered hot from resulting potassium chloride and the alcohol is distilled from the filtrate. The resulting residual ester is purified by crystallization or distillation. Bp 207°... 

As already mentioned in the preparation of acetonitrile, a halogen united with aliphatic residues may generally be replaced by the cyanogen group, on heating with potassium or silver cyanide. If alcohol and sulphuric add or ethylsulphuric add are now allowed to act on the cyanacetic add, three reactions take place. At first there is an esterification in accordance with the equation ... 

To 1 to 5 mi of ethanolic solution containing 0 4 to 0 8 mg of the quinone, add 3 ml of a mixture of equal volumes of 95 per cent ethanol and strong ammonia solution. Add 3 to 5 drops of ethyl cyanacetate and allow the mixture to stand for exactly half a minute. Add 5 ml of 6N potassium hydroxide, mix, and leave for fifteen minutes, preferably out of direct sunlight. Dilute to 50 ml and measure the extinction at 445 mjLt, Read off the quantity of quinone from a previously prepared graph. 

---