170 GLYCERIN. 



Dichlorhydrine, C 3 H 6 C1 2 == C 3 H 5 C1 2 .OH, is formed 

 by continued heating of glycerin with from twelve to 

 fifteen times its volume of fuming hydrochloric acid. 

 Is most easily ^prepared by saturating a mixture of 

 equal volumes of glycerin and glacial acetic acid with 

 hydrochloric acid at 100. On subsequently distilling, 

 that portion, which passes over between 140-200, is 

 collected separately and purified by washing with 

 water and sodium carbonate, and partial distillation. 

 Oil of an ethereal odor. The crude product appears to 

 consist of two isomeric modifications, one of which boils 

 at 174-178, the other at 182-184. Is converted into 

 isopropyl alcohol by treatment with sodium-amalgam. 

 Treated with sodium it yields allyl alcohol. Heated 

 with potassium cyanide it is converted into dicyanhy- 

 drine C 3 H 5 (CN) 2 OH. Is converted into epichlorhydrine 

 (monochlorhydroglycide) C 3 H 5 C10 by the action of 

 aqueous alkalies : a liquid boiling at 118-119, which 

 combines with hydrochloric acid with evolution of 

 heat to reform dichlorhydrine, and yields epicyanhy- 

 drine C 3 H 5 (CN)0 (lustrous crystals, fusing at 162), when 

 heated with potassium cyanide. 



Trichlorhydrine, C 3 H 5 C1 3 , is formed when the pre- 

 ceding compounds are treated with phosphorus chlo- 

 ride. Colorless liquid, boiling at 158. Treated with 

 sodium or potassium hydroxide, it yields epidichlor- 

 hydrine (dichlorhydroglycide) C 3 H 4 C1 2 , which is also 

 produced, together with the isomeric substance acro- 

 lein chloride, by the action of phosphorus chloride on 

 acrolein (p. 128). Colorless liquid, boiling at 101-102. 

 Combines directly with 1 molecule chlorine or bromine 

 and with hydrogen acids. 



Hydrobromic acid and phosphorus bromide act on 

 glycerin in the same way. 



Bromhydrine, C 3 H 5 Br(OH) 2 , and Dibromhydrine, 



OTOBr^OH, are colorless liquids. The former boils at 

 180, the latter at 219. 



