1904-5.] A New Method of Preparing Esters. 
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A New Method of Preparing Esters. By W. W. Taylor. 
Communicated by Professor Crum Brown, F.K.S. 
(Head June 5, 1905.) 
In the preparation of esters, one of the main difficulties is the 
removal of the water produced by the interaction of the acid and 
the alcohol. This difficulty is very pronounced in the case of 
those esters which are readily hydrolysed, e.g. oxalic and tartaric 
esters ; the methods of preparation of such esters are long and 
troublesome, and the yields are not always satisfactory. The 
method described in this paper is rapid and easy, requires little 
attention, and gives satisfactory yields. 
The essential idea of the process is to remove the water 
produced in the reaction between the alcohol and the acid, by the 
addition of benzen, and distillation of the ternary mixture of 
benzen, alcohol, and water. Young, in his paper, “The Preparation 
of Absolute Alcohol from Strong Spirit,”* showed that when a 
mixture of ethyl alcohol, benzen, and water is fractionated, a 
mixture of all three distils first at 64*85° C. ; followed by the 
binary mixture — alcohol, benzen at 68*25° C., or water, benzen at 
69*25°. In this way he obtained absolute alcohol from aqueous 
alcohol by careful fractionation, after addition of a sufficient 
quantity of benzen. Since methyl alcohol does not form a ternary 
mixture with water and benzen, the method cannot be employed 
for the preparation of methyl esters, nor can it be used unless the 
acid and the ester are sufficiently non-volatile not to distil over 
with the ternary mixture. 
It was at first thought that the use of hydrochloric acid or 
sulphuric acid as catalyser might be dispensed with if the benzen 
was continuously dropped into the mixture of alcohol and acid, 
and the ternary mixture removed. As a rule, the reaction 
proceeded too slowly aud too irregularly, and it was necessary to 
add a small quantity of aqueous or alcoholic solution of hydro- 
chloric acid. It was also found impracticable to carry out the 
continuous process. 
* Chem. Soc. Journ., 81, p. 707, 1902. 
