232 PROCEEDINGS OF THE AMERICAN ACADEMY 



Parachlorbenzophenone. 



From alcohol in leaflets melting at 78°. Readily soluble in alcohol, 

 ether, benzol, chloroform, and ligroiue. Analyses : — 



0.2429 gr. substance gave 0.6439 gr. C0 2 and 0.0942 gr. H 2 0. 

 0.1954 gr. gave 0.1280 gr. AgCl. 



The results of our investigations show that the formation of acid 

 anhydrides invariably precedes that of the phenoues. In the case of 

 the substituted derivatives two classes of reactions are possible ; viz. 

 the combination of substituted anhydrides with hydrocarbons : 



C 6 H 4 ' 



CO 

 \ 

 / 



CH (CO 



64 ") X 



+ 2 C 6 H 6 _ 2 C 6 H 4 j C0CeH5 + NA 



or benzoic anhydride with the substituted hydrocarbon : 

 C 6 H 6 CO 



) O + 2 C 6 H 5 X = 2 C 6 H 4 1 eoC 6 H 5 + H 2 6. 

 C 6 H 5 CO 



In the first instance the nature and position of the substituting 

 radical appear to exercise a decided influence upon the course of the 

 reaction. The orthobrom and orthonitro anhydrides react with 

 difficulty, possibly owing to the formation of condensation or decom- 

 position products between the adjacent side chains. Orthochlor anhy- 

 dride reacts somewhat more readily. All the meta anhydrides give 

 good yields of pheuones ; the para compounds, however, work best 

 of all. 



The essential conditions of the process appear to be, first, the 

 presence of a negative radical in the acid anhydride ; second, the 

 farther this radical is removed from the carbonyl group the more com- 

 plete will be the reaction. 



