1880.] -^*^ [Greene. 



On the Action of Hyclrocliloric Acid and of Chlorine on Acetobenzoic 

 Anhydride. By Win. H. Greene, 31. D. 



(Read before the American Philosophical Society, March 19, 1880.) 



In September last, M. Loir published, in the Bulletin de la Societe Chim- 

 ique, a paper upon the double function (alcohol and aldehyde) of various 

 acids and anhydrides. I will not discuss the general conclusions of this 

 article, which has found its way into many of the collections of scientific 

 literature, but the paper contains grave errors upon certain of the reactions 

 of acetobenzoic anhydride. According to M. Loir, this compound behaves 

 differently with hydrochloric acid and with chlorine, accordingly as it has 

 been prepared by the action of acetyl chloride upon sodium benzoate, or of 

 benzoyl chloride upon sodium acetate. Made by the last of these processes, 

 it is decomposed by hydrochloric acid at 130°, into acetyl chloride and ben- 

 zoic acid : chlorine at 140° converts it into acetyl chloride and chloroben- 

 zoic acid. Under the same circumstances, the anhydride prepared by the 

 first process is unaffected, but at 160° hydrochloric acid converts it into 

 benzoyl chloride and acetic acid; at 170° under the action of chlorine it 

 yields benzoyl chloride and chloracelic acid. 



Acetobenzoic anhydride begins to decompose at a temperature below 150°, 

 into acetic anhydride and benzoic anhydride, and at temperatures near this 

 point it should act as would a mixture of the latter two bodies. Under the 

 influence of hydrochloric acid it should yield acetyl chloride, acetic acid, 

 benzoyl chloride and benzoic acid. Chlorine should act in an analogous 

 manner. I have repeated the experiments of M. Loir, with the following 

 results : 



If dry hydrochloric acid be passed into acetobenzoic anhydride, at ordi- 

 nary temperatures, the reaction is the same, by whichever pi'ocess the an- 

 hydride may have been prepared : benzoic acid is deposited, and the tube 

 conveying the hydrochloric acid becomes obstructed. On raising the tem- 

 perature, . acetyl chloride begins to distill at 55-60°, and the product 

 obtained up to 130° is a mixture of acetyl chloride and acetic acid. If the 

 heat be raised much above 130°, and if the current of hydrochloric acid be 

 rapid, a small quantity of benzoyl chloride is carried over, and will be 

 found in the distillate. The residue in the apparatus consists of benzoyl 

 chloride and benzoic acid. If the anhydride be heated to 130°, or any other 

 temperature, before passing the hydrochloric acid, the reaction is the same 

 with the anhydride prepared by each process. However, it seems that the 

 lower the temperature the greater the proportions of acetyl chloride and 

 benzoic acid which are formed, while <at higher temperatures (130-150°), 

 the reaction yields acetyl chloride, acetic acid, benzoyl chloride and ben- 

 zoic acid in about equivalent proportions. 



Chlorine acts in an analogous manner : the products are the same 

 in Avhichever manner the anhj'dride may have been prepared ; but, with 

 the exception of the acetyl chloride, these products are more difficult to 



