306 KESORCIN. 



methylsulphate at 170-180 ; subjecting guaiacum 

 to destructive distillation ; and is contained in beech- 

 wood tar (creosote). Colorless liquid, boiling at 

 200. Slightly soluble in water, easily soluble in 

 acetic acid and alkalies. Forms, like phenol, crystal- 

 lizing, easily soluble, and easily decomposable salts 

 with the alkalies and with ammonia. When heated 

 with hydriodic acid (or iodine and phosphorus) it 

 yields methyl iodide and pyrocatechin. The latter 

 substance is also produced when guaiacol is added to 

 fusing potassium hydroxide. 



Pyrocatechin-dimethylether, C 6 H 4 (O.CH 3 ) 2 . Is 

 obtained by heating guaiacol-potassium with methyl 

 iodide. Liquid, boiling at 205-206. 



Diacetylpyrocatechin, C 6 H 4 (O.C 2 H 3 0) 2 , is pro- 

 duced by the action of acetyl chloride on pyrocate- 

 chin. Needles, easily fusible, insoluble in water, solu- 

 ble in alcohol. 



Tetrabrompyrocatechin, C 6 Br 4 (OH) 2 , is produced 

 when pyrocatechin is mixed with an excess of bro- 

 mine. Reddish-brown, rhombic needles, insoluble in 

 water, soluble in alcohol. 



c. Resorcin (Para-dioxybenzene). Is formed by 

 adding a number of resins (galbanum, assafoetida, 

 sagapenum, acaroid) to fusing caustic potassa ; is ex- 

 tracted from the fused mass by acidifying with sul- 

 phuric acid and shaking with ether, and purified by 

 distillation. Is further produced from parachlor- and 

 parabromsulphobenzolic acids, paradisulphobenzolic 

 acid, paraiodophenol, and parasulphophenolic acid by 

 fusing with caustic potassa. Plates or columns, easily 

 soluble in water, alcohol, and ether. Fuses at 104, 

 and boils at 271, evaporates at a lower temperature. 

 The aqueous solution is colored dark-purple by iron 

 chloride. 



