Phelps and Tillotson, Jr. — Malonic Acid. 251 



1*25 grm. loss in the process of recovery, taken up by the sodium 

 carbonate water, and recovered as malonic acid by the ether 

 extraction. Taking, for example, experiment (2) of series C in 

 Table II, of the 0*40 grm. of malonic acid recovered from the 

 wash water, 0*30 grm. was presumably due to the action of the 

 sodium carbonate on the ester during the process of shaking 

 out with ether. • We have then, 73*94 grm. of ester found, 1*25 

 grm. of ester lost during the process of recovering the ester and 

 acid, corresponding to 0*13 grm. of ester, remaining unesterified. 

 The total, therefore, of ester accounted for is 75*32 grm. or 

 97*9 per cent, leaving 2*1 per cent lost, probably through decom- 

 position. In this particular experiment, as well as in experi- 

 ment (1) of series C, a part of the loss is due to vaporization of 

 ester during the interpolated treatments under diminished 

 pressure. 



From the results shown in Table II it is evident that under 

 conditions which give the best yield, not more than 0*10 grm. of 

 malonic acid remains unesterified, and, further, that about 

 1 grm. or two per cent of acid is lost through decomposition. 

 Under conditions less favorable for theoretical yields, a larger 

 amount of acid remains unesterified, and at the same time the 

 amount lost by decomposition is greater. Comparing experi- 

 ments (2) and (3) of series B, it is evident that increasing the 

 amount of alcohol with which the malonic acid is treated on 

 the water bath, from 60 cm3 to 100 cm3 , increases the yield by one 

 per cent, while if malonic acid is treated with several portions 

 of alcohol as described above, and shown in experiments (1) 

 and (2) of series C, or if the time of driving over the second 

 portion of alcohol is increased as in experiment (5) of series 



B, a much larger yield of ester is obtained. Merely increas- 

 ing the amount of alcohol distilled over, as in experiment (6) 

 of series B, gives no better yield than under otherwise similar 

 conditions in experiment (5). In experiments (1), (4) and (7) 

 it is plain that with small amounts of sulphuric acid, esterifi- 

 cation is not complete, while with larger amounts the yield of 

 ester is apparently not quite as good as that produced by two 

 grams. By varying the time in experiments (3), (4) and (5) of 

 series B, a larger yield of ester is obtained, with increase in 

 the time taken to distil the second portion of alcohol, while if 

 the alcoholic solution of malonic acid is heated for a longer 

 time on the water bath, as in experiments (1) and (2) of series 



C, the yield is materially increased. 



The ester obtained in all the experiments of Tables I and II 

 was found to be in a high state of purity, since, on redistilla- 

 tion, it showed no considerable variation in boiling point 



From the work here described, it may be seen that in gen- 

 eral, increasing within limits the amount of alcohol used, and 



