458 Proceedings- of the lixyyal Irish Academy. 



suspended iu a mixtiue of lOce. of eoueenti-ated sulphuiie acid and lOOejj. 

 of water. Asolatiou of 6 grams of sodium nifci-ite in. 20 e.c. of water was 

 added very slowlj, the mixture being cooled wiih water and \'igorously 

 shaken during the addition, wliich lasted about one hour; Tlie pi-odnct was 

 then allowed to remain at the room temperattire for an hour more, and was 

 then filtered, washed with a litile alcohol, and afterwards witli a little ether. 

 The diazouium-salt consisted of bright-browji: needles, which decomposed at 

 about 165^0. 



The diasonitim ddoi-ide was prepared bj- the method of Sachs and Hilpert 

 (loe. eit.). It consisted of oiunge-yellow flakes, decomposing at about 144°C. 



2-A^itrostilhene. 



Five grams of 2-uifcrostilbene-4-diazonium-snlphate in powder form wei-e 

 added gradually to 40 c.c. of hot absolute alcohol coutaiiiing a little sulphniie 

 acid, and the mixture was boiled under reflux for two hours. A clear brown 

 solution resulted, together with some tar, and when it liad cooled the solution 

 was poured off. On addition of a little water a brown precipitate was de^ 

 posited. This contained scai-cely any nitrostilbena The filti-ate from the 

 above solid was precipitated with a lai-ge volume of water, an oily solid l>eing 

 thrown down which solidified on standing. The latter precipitate on crystal- 

 lization from alcohol yielded bright-yellow needles melting at 76^C. The 

 yield was 1-15 grams. 



2-AriiinostiIbciie. 



2-AminostiIbene may be prepared by the niethwl of Sachs and Hilpert 

 (lac. cit.), or by the following modification :— 



Five gi-ams of 2-uitrostilbene were dissolved in 20 c.a of glacial acetic 

 acid, and treated with a solution of 16 gi-auis of stannous chloride in 42 c.c. 

 of glacial acetic acid saturated with liydrogen chloride. Tlie solution of the 

 tin salt, at a temperatui-e of 40^ C, was added slowly to the solution of the 

 nitro-derivative, the temperature of wliich was 45"^ G., and the reaction- 

 mixture was gradually i-aised to a temperature of 90°-100'^ C , wliere it was 

 kept constant for a short time. Tiie product was then poui-ed into a shallow 

 vessel, and allowed to i-emain at the room temperature for twelve hours. The 

 precipitate formed on the addition of water was filtered from the mother 

 liquor, and extracted with ether, on evaporation of wliich 2-aminostilbene was 

 left. The amine was crystallized from alcohol, giving white leaflets, melting 

 at 106^ C. 



■ Stilbeiie. 



The diazouium sulphate of 2-aininostill>eue was obtained by the action of 

 amyl nitrite on an alcoiiol solution of the amine (Sachs and Hilpert, loc. cU.)- 



