226 PROCEEDINGS OF THE AMERICAN ACADEMY 



XV. 



CONTRIBUTION FROM THE SALISBURY LABORATORY OF THE 

 WORCESTER POLYTECHNIC INSTITUTE. 



ON THE FORMATION OF SUBSTITUTED 

 BENZOPHENONES. 



By George D. Moore and Daniel F. O'Regan. 



The preparation of benzophenone by heating benzoic acid, benzol, 

 and phosphorpentoxide in sealed tubes at 180-200° has already been 

 described by Kollarits and Merz.* The same authors t have also 

 shown that benzoic anhydride reacts, under similar conditions, in the 

 same manner as benzoic acid. We have proved t that not only ben- 

 zoic acid, but also the three isomeric mouo-nitro, chlor, and brom acids 

 yield anhydrides as the first product of this reaction. In the present 

 paper we will describe the preparation of the nitro, chlor, and brom 

 benzophenones from these anhydrides. 



I. Action of Phosphorpentoxide upon Orthonitrobenzoic Anhydride 



in an Excess of Benzol. 



10 grams of orthonitrobenzoic anhydride, m.pt. 133°, prepared by 

 boiling a benzol solution of the acid with phosphorpentoxide, were 

 heated in a sealed tube with 15 grams phosphoric anhydride and 

 25-30 c.c. pure dry benzol at 150° for about four hours. A slight 

 reaction takes place in the cold, as evidenced by the rapid blackening 

 of the solid constituents of the mixture, although the benzol remains 

 uncolored. 



After heating, the dark-colored mother liquor was decanted from the 

 black residue, decolorized by means of bone-black, and concentrated 

 until, on cooling, crystals were deposited. These, after washing with 

 pure benzol and drying between filters, showed a melting point of 

 132-133°. The body is therefore the unaltered anhydride. 



The black residue was a hard, vitreous mass, which clung so tena- 

 ciously to the tube that it was necessary to crush the latter completely 



* Zeitschr. fur Chemie, 1871, p. 705. Ber. d. ch. G., V. 447. t Loc. cit. 



X These Proceedings, XXVII. 93. 



