42 Phelps and Osborne — Esterification of Benzole Acid. 



esterification, the acid alcoholic distillate was chilled with ice, 

 diluted with three or four times its volume of water, and 

 shaken out three times in a separating funnel with fresh por- 

 tions of ether. The ethereal solution thus obtained was treated 

 with an excess of sodium carbonate in solution, washed with 

 distilled water and f ractioned in vacuo in the manner described 

 above, to separate the low-boiling impurities, largely ether, 

 alcohol, and water, and finally to distil any benzoic ester. The 

 distillates in case of experiments (2), (4), (6), (8), (10) and 

 (13) of Table I were tested in this way. In no case was there 

 evidence of even the faintest trace of benzoic ester in the dis- 

 tillate. When 1 grm. of benzoic ester was mixed with 200 cm3 

 of ordinary alcohol containing 1 per cent of hydrochloric acid, 

 diluted, and treated as described in case of the distillates men- 

 tioned above, it was found that ester to the amount of 0*85 grm. 

 was recovered. 



The sources of loss in the recovery of benzoic ester were 

 studied. When 75 grm. of pure benzoic ester were shaken 

 out in a separating funnel with a solution of sodium carbonate 

 containing ice, separated from this solution, washed with dis- 

 tilled water, and united with the portions of ester carried on 

 mechanically and recovered from the water solutions by shak- 

 ing out three times with fresh portions of ether, it was found 

 that the weight of ester recovered on distilling the ethereal 

 solution under diminished pressure was less than the amount 

 taken by only 0*25 grm. 



In all of the experiments of Table I alcohol as free from 

 water as it can be made by repeated distillations over calcium 

 oxide was used. This was used alone or was charged with 

 dry hydrochloric acid in the proportions indicated in the table. 

 In experiment (1) of Table I all low-boiling impurities were 

 removed from the material remaining in the second flask by a 

 vacuum fractionation. Then all material that would distil at 

 the higher heat (150°) of the acid bath was collected in the 

 100 cm3 flask. After diluting this material with water, extract- 

 ing with ether three times and fractioning in vacuo, it was 

 found that only enough benzoic ester remained in the receiver 

 to give odor. In the remaining experiments of series A of 

 the table the ester found in the second flask at the end of the 

 time indicated was recovered without further treatment; in 

 series B water and all other material found with the ester were 

 removed so far as possible by fractioning in vacuo. This was 

 done by heating the flask in which esterification took place in 

 a water batli finally at 60° with the pressure on the manometer 

 registering 15 mm , this pressure and temperature being main- 

 tained fifteen minutes. A fresh portion of alcohol with 

 hydrochloric acid was then driven into the portion remaining 



