115 



Nitro-terephthalic acid is readily soluble in warm alcohol and in 

 warm water, and possesses the bibasic character of the terephthalic 

 acid in a much higher degree. It forms well-defined crystallizable 

 acid and neutral salts. The ethers of this acid are likewise crystal 

 lizable. They differ, however, from the terephthalic acid ethers by 

 their greater solubility in alcohol and their depressed fusing-point. 



Chloride of terephthalyl (C 8 H 4 O 2 CP) is obtained, together with 

 oxychloride of phosphorus (hydrochloric acid being evolved), when 

 terephthalic acid is acted upon with pentachloride of phosphorus at a 

 temperature of 40 (Cent.). Chloride of terephthalyl is a solid and 

 beautifully crystalline substance, without odour at the ordinary 

 temperature, but evolving, when heated, a very pungent smell like 

 that of chloride of benzoyl, which it resembles in all its reactions. 

 With the alcohols it forms terephthalic ethers, with ammonia an 

 amide, and with the organic bases compound amides* Terephthalyl- 

 amide, C 8 H 8 N 2 O 2 , can only be obtained by acting with chloride of 

 terephthalyl on ammonia ; it is a white amorphous substance insoluble 

 in all solvents. Terephthalylamide, when treated with fuming nitric 

 acid, yields nitro- terephthalic amide, C 8 H 8 (NO 2 ) N a O 3 , which 

 crystallizes in beautiful prisms. 



Terephthalamide shows a remarkable resemblance to benzamide 

 when treated with substances capable of abstracting the elements of 

 water. It loses two equivalents of water (H 2 0), and is converted 

 into terephthalylnitril, C 8 H 4 N 2 . This remarkable substance is best 

 formed by the action of anhydrous phosphoric acid on terephthalamide. 

 It distils over in form of a liquid, which solidifies in the neck of the 

 retort. 



Terephthalylnitril is colourless and without odour, and forms 

 beautiful prismatic crystals. It is insoluble in water, readily soluble 

 in boiling alcohol, less soluble in cold alcohol, and insoluble in benzol. 

 When boiled with caustic alkalies, it is gradually decomposed, 

 ammonia is given off, and terephthalic acid is reproduced. 



It is obvious that terephthalylnitril, like all similar substances, 

 may be considered as a cyanogen compound, which in this instance 

 would be the cyanide of the bibasic radical phenylen, C 6 H 4 , which is 

 not yet discovered. If we could succeed in obtaining phenylen, the 

 artificial production of terephthalic acid or an isomeric would probably 

 be attended with little difficulty. 



