374 Drtisfiel and Bancroft — Esters Derived from the 



always with the same result, and the product was used in the 

 preparation of ethylene glycol. Also on saturating a portion 

 of the product with dry hydrobromic acid gas the yS-brom-ethyl 

 acetate was formed. 



Finally, a direct esteriiication method was devised for the 

 preparation of the yS-hydroxy ethyl acetate, which is really a 

 modification of that given by Lourenco,* to which reference 

 has already been made. Equimolecular portions of ethylene 

 glycol and glacial acetic acid were digested over twice the 

 theoretical quantity of anhydrous copper sulphate in a fiask 

 over a free fiame for eight hours. In order to keep track of 

 the esterification, one cubic centimeter of the reaction mixture 

 was pipetted into a graduated flask before heating and the vol- 

 ume made up to SSO'^^l Aliquot portions of fifty cubic centi- 

 meters were withdrawn and titrated with decinormal sodium 

 hydroxide. Other portions of the reaction mixture were with- 

 drawn from time to time and treated as described above. At 

 the end of eight hours the titration showed that the esterifica- 

 tion was practically complete. The esteritied mixture was 

 cooled and decanted, and the copper sulphate residue was 

 extracted with ether. The mixture was then fractionally dis- 

 tilled, the main portion coming over at 185°-190°, and on 

 refractionating boiled at 18T°-189°. This portion reacted 

 vigorously with acetyl chloride, effervescing briskly with evo- 

 lution of liydrochloric acid gas. 



Weighed portions of this ester were placed in flasks and 

 saponified with an excess of decinormal sodium hydroxide, 

 according to the following equation : 



CIIOH CH.OH 



I +NaOH > I +CH3.C0.0Na- 



CH,.0.C0.CH3 CH^H 



The excess of sodium hydroxide was then titrated w^ith deci- 

 normal hydrochloric acid using phenol phthalein as an indi- 

 cator. From results obtained the ester was shown to be 99'38 

 per cent pure. 



The use of anhydrous copper sulphate as a dehydrating 

 agentf in the esterification of certain hydroxy-acids has been 

 previously described in the literature. In the present investi- 

 gation this dehydrating agent is used for the first time in the 

 esterification of polyhydric alcohols. 



Another point worthy of mention in connection with the 

 preparation of this compound is the low boiling point given by 

 the various investigators. Atkinson gives 182°, De Mole 

 180°-182°, and Lourengo 180°, as the boiling point of their 



■^ Loc. cit. 



f Bogojawlensky and Naibut, Ber. d. d. Chem. Gesell., xxxviii, 3344, 1895. 

 Clemmenson and Heitraan, Amer. Chem. J., xlii, 319, 1909. Dean, this 

 Journal, xxxvii, 332, 1914. Drushel, ibid., xxxix, 114-117, 1915. 



