ISDN API! TIIOL. 399 



2. Isonaphthol (s-Naphthol). 

 C io H 8 ^ C 10 H 7 .OH. 



Is obtained, like naphthol, from potassium /3-sulpho- 

 naphthalate. Small, colorless, rhombic plates ; fusing 

 point, 122 ; boiling point, 285-290 ; easily sublim- 

 able. Difficultly soluble in boiling water ; easily in 

 alcohol and ether. 



The derivatives of isonaphthol are prepared like 

 those of n^phthol. 



Isonaphthol-ethylether, C 10 H 7 .O.C 2 H 5 . Colorless, 

 crystalline mass ; fusing point, 33. 



Isonaphthpl-acetate, C 10 II 7 .O.C 2 II 3 0. Small, color 

 less needles ; fusing point, 60. 



Dinitro-isonaphthol, C 10 H 5 (N0 2 ) 2 .OH. Is obtained 

 by warming an alcoholic solution of isonaphthol with 

 dilute nitric acid. Lustrous, bright-yellow needles ; 

 fusing point, 195. 



iOTT 

 S0 2 .OII. 



Small, colorless laminated crystals ; fusing point, 125 ; 

 not deliquescent, but easily soluble in water and alco 

 hol. The aqueous solution turns slightly green on the 

 addition of iron chloride, and, when heated with it, it 

 deposits brown nocks. 



Isonaphthyl sulphydrate, C 10 H 7 .SH. Small, lus 

 trous scales ; fusing point, 136 ; not volatile with water 

 vapor ; insoluble in water ; easily soluble in ether and 

 alcohol. 



3. Dioxynaphthalene. 

 C 10 H 8 2 = C IO H 6 (OH) 2 . 



Is obtained by melting potassium disulphonaphtha- 

 late with potassium hydroxide. Colorless needles, 

 which become violet in the air; difficultly soluble in 

 water, easily in alcohol and ether ; s.ublimable ; in an 

 alkaline solution it absorbs oxygen rapidly from the 

 air, and turns black. 



