302 QUINHYDRONE. 



distillation of quinic acid with a chlorine-mixture. 

 Monochlorquinone C 6 H 3 C10 2 . Long, yellow needles. 

 Dichlorquinone C 6 H 2 C1 2 2 . Is also produced hy the ac- 

 tion of chlorous anhydride on benzene ; and hy treat- 

 ing trichlorphenol with nitric acid. Large, yellow 

 prisms ; fusing point, 120. Trichlorquinone C 6 HC1 3 2 . 

 Large, yellow laminae, almost insoluble in water ; fus- 

 ing point, 165-166. Tetrachlorquinone (chloranile), 

 C^C^O 2 , is produced, together with trichlorquinone, also 

 from a number of other organic compounds (phenol, 

 anilin, salicylic acid, isatine, etc.) hy treatment with 

 chlorine, or hydrochloric acid and potassium chlorate. 

 Yellow, lamellar crystals, sublimahle without decom- 

 position, insoluble in water, but slightly soluble in 

 cold alcohol, more readily in hot. Heated with phos- 

 phorus pentachloride, it yields perchlorbenzene, (C 6 C1 6 ) 

 (p. 254). Dissolves in dilute caustic potassa, thus caus- 

 ing the formation of potassium chloride and the diffi- 

 cultly soluble purplish-red potassium salt of chlorani- 

 lic acid, C 6 C1 2 (OK) 2 2 + H 2 0, from which by means' of 

 sulphuric acid the free acid, C 6 C1 2 (OH) 2 2 + H 2 0, may 

 be obtained in the form of reddish-white, shiny scales, 

 resembling mica. The same acid is also obtained by 

 treating trichlorquinone in the same way. 



ftllinhydrone (Green hydroquinone), C 12 H 10 4 , is 

 formed by the action of an insufficient quantity of sul- 

 phurous acid on a solution of quinone ; or by mixing 

 solutions of quinone and hydroquinone ; and may hence 

 be considered as a compound of equal molecules of 



quinone and hydroquinone : C 6 II 4 < QTT'TTQ [ C 6 H 4 . In 



general terms, it is always produced when hydrogen is 

 eliminated from hydroquinone, as, for instance, by means 

 of chlorine water, iron chloride, nitric acid, etc. Long, 

 thin prisms of a beautiful green metallic lustre, of an 

 odor somewhat resembling that of quinone. It fuses 

 easily, sublimes partially, is slightly soluble in water, 

 easily in alcohol, forming a yellow solution. Further 

 treatment with oxidizing. substances converts it readily 

 into quinone ; with reducing agents into hydroquinone. 



