PKelps and Tillotson, Jr. — Malonic Acid. 247 



over, except in experiments (5), (9), (10), (21) and (22), where 

 the treatment was special. In experiment (5) the malonic 

 acid, dissolved in the first portion of alcohol shown in the 

 table, and contained in the 500 cin3 round-bottomed flask, was 

 heated on a water bath at 50° for three hours, then connected 

 with a vacuum pump and heated with the water bath at the 

 same temperature until 40 cm3 of liquid, consisting, presumably, 

 of water and alcohol, had distilled over. The second portion 

 of alcohol w T as then added and the heating on the water bath 

 at 50° continued for four hours, after which about 80 cm3 of 

 liquid was removed under diminished pressure as before. 

 Finally, 40 cm3 of the third portion of alcohol shown in the 

 table was added and the process of esterification completed in 

 the same manner as in the other experiments. In experiments 

 (9) and (10) the current of alcohol vapor at first was slow; 

 in the case of experiment (9), for fifteen minutes ; in the case 

 of experiment (10), for an hour, and more rapid for the remain- 

 der of the time. In experiment (21), after treatment in the 

 usual manner with the first portion of alcohol, the low-boiling 

 products were removed under diminished pressure by heating 

 the esterification flask on a water bath at 60° till the manome- 

 ter showed a pressure of 15 mm for fifteen minutes, and the proc- 

 ess of esterification w T as repeated with the second portion of 

 alcohol, shown in the table. In experiment (22) the malonic 

 acid, zinc chloride and 200 cm3 of alcohol were boiled in the 

 500 cm3 round-bottomed flask under a return condenser for 

 forty-five minutes before continuing the esterification with the 

 second portion of alcohol in the usual manner. 



To learn whether any ester had distilled with the alcohol 

 during the esterification, several of the alcoholic distillates 

 were cooled with ice diluted w T ith three or four times its 

 volume of water and shaken out separately three times with 

 fresh portions of ether, washing the collected portion with a 

 solution of sodium carbonate, and, finally, with pure water. 

 The combined ether solutions were then fractioned in vacuo as 

 described above. In no case was malonic ester found in the 

 distillates tested. The loss inherent in the process employed 

 for recovering the pure ester from the crude material, produced 

 in the esterification flask, was determined by treating 75 grm. 

 of pure malonic ester by the same procedure, described above, 

 for the crude material. The loss amounted to 1*25 grm. 

 of malonic ester. 



From experiments (1), (2), (3) and (1) of Table I it is plain 

 that an increase in either the amount of alcohol containing 

 hydrochloric acid, or the time of- action, gives an increase in 

 the amount of ester produced. Comparing experiments (1) 

 and (7), absolute alcohol alone, in the absence of zinc chloride, 



