[ruttan-roebuck] esters OF ETHYLENE GLYCOL 3 



near the melting point of the ester. The distearate and the di-palmi- 

 tate were prepared by this method only in small quantity as a con- 

 firmation of the less laborious method from glycol and the acid. 



In the preparation of the di-stearate and di-palmitate from the 

 above reaction mixtures, search was made for the necessary inter- 

 mediate product, with only one bromine of the ethylene bromide 

 replaced (C2 H4 Br Cis H35 O2), but without success. In order to 

 remove the product of the first step as quickly as possible from 

 contact with the silver salt, the reaction was repeated, allowing 

 the hot ethylene bromide from a return condenser to drip 

 through a Gooch crucible containing compressed pellets, but none 

 of the bromide stéarate could be found in the resulting product. 

 Apparently the second step in the reaction is of much greater velocity 

 than the first under the conditions employed. The similar chloride 

 stéarate (C2 H4 Cl Cis H35 O2) described below is quite stable and readily 

 made from the acid and glycol monochlorhydrin. 



The most convenient method of preparation of both mono- 

 and di-esters of stearic and palmitic acids was found to be the reaction 

 between glycol and the fatty acid at a temperature of 10-12°C. below 

 the boiling point of the glycol (197°C). About 30 grammes of the 

 acid was mixed with an amount of glycol more than required to con- 

 vert all the acid into the monoester; this proved a convenient quantity 

 for each charge. In our first experiments this mixture was heated in 

 an open short necked glass flask placed in a double walled copper 

 vessel, a Victor Meyer drying oven, the annular space of the latter 

 being partly filled with boiling aniline, connected with a return con- 

 denser. The glycol and the fused acid form two layers, the mono and 

 di-esters formed mix with the acid, and the water formed escaped as 

 vapour. The yield of esters was materially increased and the time of 

 reaction shortened by stirring strongly with a platinum stirrer, rotated 

 by an air motor. The heating was continued 4-7 hours, a bead of 

 glycol always remained on cooling, and 5-10% of the acid remained 

 uncombined. In later experiments a large flask carrying 100 grms. 

 of the acid was heated to about 180-190°C. in a Fries electric oven, 

 and kept thoroughly stirred by a platinum spindle and blade, passing 

 through the opening at the top and rotated by an electric motor. 

 The mixture from the fusion was freed from glycol by washing two 

 to three times with hot water allowing to cool and removing the cake 

 of fat. The excess of acid was determined by titration and was separ- 

 ated by fusing on the water bath with an equivalent of calcium 

 hydrate, extracting with ether and filtering hot. The ether was evap- 

 orated and the residue dissolved in hot alcohol. This solution was 

 allowed to cool slowly and successive crops of crystals filtered off at 



