228 PROCEEDINGS OF THE AMERICAN ACADEMY 



The first of these reactions may account for the free acid which is 

 obtained, as above mentioned, by the action of dilute alkalies on the 

 raw product. Unchanged anhydride would, however, give the same 

 result, and it is quite possible that appreciable quantities thereof may 

 easily have been retained in the black residue after its treatment with 

 benzol, owing to its gummy vitreous nature. 



II. Action of Phosphorpentoxide upon Metanitrobenzoic Anhydride 



in an Excess of Benzol. 



6 grams of metanitrobenzoic anhydride, m.pt. 161°, prepared by 

 boiling a benzol solution of the acid with phosphorpentoxide, were 

 heated in a sealed tube with 5 grams phosphoric anhydride, and 

 25-30 c.c. pure dry benzol for about four hours at 190-200 3 . After 

 the reaction was completed, the contents of the tube consisted of a 

 hard black vitreous residue, and a brownish supernatant liquid. This 

 last was poured off, the residue washed several times with clean benzol, 

 and the washings added to the decanted portion. The liquid was 

 then purified by means of bone-black, and, after concentration, 

 threw down a precipitate of fine white needles which, by their melfr- 

 ing point, 161°, and ready solubility in alkalies, were easily identified 

 as metanitrobenzoic anhydride. 



The black vitreous residue from the benzol mother liquor was 

 pulverized, freed from benzol as completely as possible by pressing 

 between filters, and then extracted, first with potash to remove pos- 

 sible traces of acid and anhydride, then by repeated boiling with 

 absolute alcohol. The dark red alcoholic extract gave, after treat- 

 ment with bone-black and concentrating, a deposit of dark brown 

 prismatic crystals, melting at 89°. By repeated crystallization from 

 absolute alcohol these were finally obtained pure in the form of gray- 

 ish white scales or leaflets, melting at 94-95°. The analyses gave 

 the following values : — 



& 



0.2086 gr. substance gave 0.5248 gr. C0 2 and 0.0809 gr. H 2 0. 

 0.2044 gr. substance gave 10.4 c.c. nitrogen gas at 10°. 4 and 

 757.3 mm. 



