262 Phelps and Tillotson, Jr. — Cyanacetic Ester. 



of water, alcohol, hydrochloric acid and all low-boiling pro- 

 ducts were removed under diminished pressure by heating the 

 nask with a water bath at 50°. The residue, consisting, pre- 

 sumably, of imido ester hydrochloride, was then treated on 

 the esterihcation apparatus as described above. The result 

 indicates that, if hydrochloric acid is not present in sufficient 

 amount, ethyl alcohol at a temperature of 100°-110° does not 

 complete the reaction, while if large amounts of hydrochloric 

 acid are present as in the other experiments of the table, the 

 reaction proceeds at a temperature of 60°-70°. Experiment 

 (2) of series B, which was treated with hydrochloric acid at 

 the boiling temperature of the alcohol, shows not quite so 

 good a yield as experiment (1) of series B, which was first 

 saturated in the cold. The presence of large amounts of cat- 

 alyzers in experiment (3) of series B produces a lower yield 

 than that obtained in experiment (1) of series B, possibly 

 through the formation of larger amounts of water and subse- 

 quent decomposition of malonic ester. 



The experiments in Table II, in which sulphuric acid was 

 used as a catalyzer, show the same general results as those of 

 Table I. Better yields are obtained when no water is added, 

 as in experiments (7) and (8) of series A and (1), (2) and (3) of 

 series B, than in the remaining experiments where water was 

 used. In experiment (1) of series A, sulphuric acid alone pro- 

 duced no apparent conversion to malonic ester at the temper- 

 ature of a water bath, but when hydrochloric acid was passed 

 in, the ammonium salt was precipitated and malonic ester was 

 formed. Experiment (7) of series A, which was esterified 

 after saturation, shows a slightly better yield than experiment 

 (8) of series A, which was shaken out directlv after saturation 

 and treatment on the return condenser. In series B the dif- 

 ference is more marked in the case of experiments (1) and (2), 

 respectively, which were similarly treated. In experiment (3) 

 of series B, in which the gaseous hydrochloric acid was passed 

 into a boiling alcoholic solution, the yield is much lower than in 

 experiments (1) and (2) of series B, which were first saturated 

 in the cold. 



The work here recorded has shown that the conversion of 

 cyanacetic ester to malonic ester is apparently not effected at 

 the temperature of a water bath by sulphuric acid, and that in 

 the absence of large amounts of hydrochloric acid it proceeds 

 slowly, if at all, at 110°. However in the presence of large 

 amounts of hydrochloric acid, with or without additional cata- 

 lyzers, the reaction proceeds rapidly at the temperature of the 

 boiling alcoholic solution. It has been shown that, in the pres- 

 ence of one or two molecules of water, high yields of malonic 

 ester may be obtained, but that better yields result if no water 



