CINNAMIC ACID. 375 



prisms; fusing point, 39; distillable without decom- 

 position only in a vacuum. 



Styryl cinnamate (Styracin), C 9 H 7 2 .C 9 H 9 , is con- 

 tained in the brown resin, the residue from the prepa- 

 ration of cinnamic acid from storax. Can be most 

 readily prepared by digesting storax with dilute soda- 

 ley, at a temperature not higher than 30, until the 

 residual styracin has become colorless. After it is 

 washed out and dried, it is recrystallized from alcohol, 

 which contains ether. Fine, colorless needles, united 

 in nodules, insoluble in water ; fuses at 50. 



Nitrocinnamic acid, C 9 H 7 (I^"0 2 )0 2 . When nitric 

 acid is allowed to act upon cinnamic acid, two nitro- 

 acids are formed, which can be separated by means of 

 crystallization. One fuses at 265, is difficultly solu- 

 ble in water, and yields paranitrobenzoic acid when 

 oxidized. The second is easily soluble in water, and 

 yields orthonitrobenzoic acid when oxidized. 



Cinnamic acid dibromide (Dibromhydrocinnarnic 

 acid), C 9 H 8 Br 2 2 == C 6 H 5 .CHBr.CHBr.CO.OH. Is 

 formed by direct union, when bromine in the form of 

 vapor is allowed to act on cinnamic acid, either at the 

 ordinary temperature or at 100. Colorless, rhombic 

 laminae; insoluble in cold water, easily soluble in 

 alcohol and ether; not fusible without decomposition; 

 when boiled with water it .is decomposed, yielding 

 /3-bromcinnamene and phenylbromlactic acid (p. 355). 

 Nascent hydrogen converts it into hydrocinnamic acid. 



Monobromcinnamic acid, C 9 H 7 Br0 2 . Two iso- 

 meric modifications of this acid are formed by the 

 addition of alcoholic potassa to a boiling-hot alcoholic 

 solution of cinnamic acid dibromide. They can be 

 separated by means of partial crystallization. The salt 

 of a-bromcinnamic acid is difficultly soluble in water, 

 that of 6-bromcinnamic acid is very easily soluble 

 and even deliquescent in the air. o.-Bromcinnamic acid 



