802 M. Voit on the Derivatives of Benxoic Acid, 



the addition of water to the acid mixture, nitrobenEoic acid alone 

 is precipitated. The acid is also obtained by adding chloride of 

 benzoyle to the acid mixture. 



The nitrobenzoic acid was converted into benzamic acid, for 

 which Voit proposes the name amidobenzoic acid, as expressing 

 its constitution better. This was effected in the usual manner 

 by treatment with sulphide of ammonium. After filtering off 

 from the separated sulphur and adding hydrochloric acid, a com- 

 pound of amidobenzoic acid with that acid is obtained. 



Of amidobenzoic acid, the silver salt alone had been hitherto 

 known. Gerland studied some compounds which it forms with 

 acids, in which it plays the part of a base. Voit describes in 

 this paper the baryta, lime, soda, magnesia, and strontia salts, 

 all of which are crystallizable, and perfectly well defined. The 

 lime and baryta salts were prepared by neutralising the hydro- 

 chloric acid compound of amidobenzoic acid with their car- 

 bonates. From the baryta salt the others were prepared. 



Binitrobenzoic acid is obtained by boiling benzoic acid with 

 a mixture of sulphuric and nitric acids until the evolution of 

 nitrous fumes ceases. On allowing the mixture to cool, the acid 

 is deposited in brilliant crystals. It is more difficultly soluble 

 in water than nitrobenzoic acid. 



By treating this acid with sulphuric acid and alcohol, oily 

 drops are formed, which on standing become solid. These drops 

 are binitrobenzoate of sethyle. It is soluble in warm alcohol, from 

 which it crystallizes on cooling in long silky needles. By treat- 

 ing this aether with an alcoholic solution of ammonia, the binitro- 

 benzamide is obtained, crystallizing in silvery scales. By acting 

 on an ammoniacal solution of binitrobenzoic acid with sulphur- 

 etted hydrogen, it is converted into binamidolensoic acid, sul- 

 phur being eliminated. On the addition of hydrochloric acid to 

 the solution filtered off from the Sulphur, green crystals of a 

 compound of hydrochloric acid and binamidobenzoic acid are 

 gradually formed. Binamidobenzoic acid is obtained in the 

 free state by digesting its compound with sulphuric acid with 

 carbonate of baryta. It crystallizes in small greenish-pointed 

 crystals, which arc soluble in water, alcohol, and £ether, tasteless, 

 and without action on vegetable colours. .,,,^ ,;, .^i 



Binamidobenzoic acid is remarkable from tne property of 

 (M)inbining with acids, which it possesses in a high degree. It 

 exhibits a similar comportment to that observed in the case of 

 aniline, — that substitution products retain in general the chief 

 character of the compound from which they are derived, but that 

 the replacing substance does not entirely lose its chemical cha- 

 racter in the substitution product, but impresses it more upon 

 the compound as the number of equivalents replaced by it in- 



