Phelps and Tillotson, Jr. — Malonic Acid or its Ester. 269 



Potassium cyanide of 96-98 per cent purity was used for 

 the experiments in series A of the table. For those of series 

 B, pure commercial cyanide containing ammonia, and for 

 those of series C, pure commercial potassium cyanide free 

 from ammonia and cyanate was employed. An analysis of the 

 sample used in the experiments in series C gave the following 

 results. 



I. 0*2372 grm. of potassium cyanide gave "4579 grm. of silver 



cyanide. CNr=37'50 per cent. 

 II. 0*2682 grm. of potassium cyanide gave -5198 grm. of silver 

 cyanide. CN = 37'65 per cent. 



Calculated for KCN, CN= 39*95 per cent. 



The alcohol made use of in the conversion to malonic ester 

 and that employed in the process of esterification was alcohol 

 of commerce, made as free from water as possible by repeated 

 distillations over calcium oxide. 



In all the experiments in the table, except those specially 

 treated, 200 grm. of monochloracetic acid, contained in a liter 

 flask, was treated with about 300 grm. of pure hydrous sodium 

 carbonate of commerce, and 50 cmS of water added to start 

 the reaction. Good results were obtained, in experiments not 

 recorded, using the anhydrous sodium carbonate dissolved in 

 250 cm3 of water. The advantage in the use of the hydrous salt 

 lies in the fact that the solution of sodium chloracetate is kept 

 cold during the process of neutralization, thus keeping the 

 hydrolysis of the chloracetate at a minimum. In fact, under 

 the above conditions, a temperature low enough to freeze the 

 mass is nearly always obtained. It is usually convenient to 

 hurry the reaction by standing the flask in water at room tem- 

 perature. In experiment (1) of series B, potassium carbonate 

 was used instead of sodium carbonate, but there appeared to 

 be no advantage in its use, since the potassium sulphate 

 formed on acidifying with sulphuric acid was not less soluble 

 than sodium sulphate under the conditions of experimentation. 

 When the chloracetic acid was entirely neutralized, the solu- 

 tion was poured into a solution of 165 grm. of potassium 

 cyanide in 250 cm3 of water heated to 70-80°, and after the 

 vigorous action had taken place, the solution was boiled for 

 about five minutes to complete the reaction. The solution 

 was then cooled and acidified with sulphuric acid, using the 

 action of a drop of the liquid with logwood paper as a test of 

 acidity. About 100 cm3 of concentrated sulphuric acid were 

 required for each experiment. After cooling the precipitated 

 salt was filtered off and the water solution evaporated to dry- 

 ness. In experiment (1) of series A, this was done at the 

 temperature of the steam bath. In the remaining experiments 



