IIyan and CuLunANK—So77te Derivatives of Stilhene. 157 



p. 554), as onv preparation contains a nitro-group in the para-position of one 

 benzene nucleus of tlie stilbene molecule., and a methoxyal-radical in the para- 

 position of the other benzene ring. 



The condensation of 2-4-6-trinitrotoluene with benzaldehyde yielded 

 2'4-6-trinitrostilbene (Pfeiffer and Monath, loc. cit.; compare Ullmann and 

 Gschwind, loc. cit.). Stannous chloride caused partial reduction of this 

 compound, giving 4-6-dinitro-2-amino-sfcilbene. Tlie sulphate of tliis amine 

 was converted by aniyl nitrite into 4-6-dinitro-stilbene-2-diazonium sulphate. 



Experimental. 



'2'4:-Di7iitros/;ilbene. 



The method employed for the preparation of this compound was that of 

 Thiele and Escales {loc. cit.) from 2'4-dinitrotoluene and benzaldehyde in the 

 presence of a little piperidine. The condensation-product, while still warm, 

 was washed a few times with methylated spirit, and the residue, after 

 recrystallization from glacial acetic acid, gave a pure product mell.ing at 

 139°-140''C. It was slightly soluble in ether, alcohol, or ehlorofiniu, but 

 dissolved readily in hot benzene, glacial acetic acid, or acetone. 



'2-Nitro-'k-aminostilhene.. 



This substance was prepared by a method similar to that of Thiele and 

 Escales {loc. cit.). Sulphuretted hydrogen was passed continuously into the 

 annnoniacal alcohol which contained the 2"4-dinitrostilbene, until almost all 

 the latter had gone into solution. The product was filtered, the residue was 

 washed with a small volume of warm alcohol, and the amine hydrochloride 

 was precipitated by passing hydrogen chloride into the filtrate. The action 

 of water on the salt gave the free base as a red powder, which, after crystal- 

 lization from alcohol, separated out in the form of bright-red prisms meltiug 

 at 110°C. 



The sulphate of 2-nitro-4-aminostilbene was produced by adding con- 

 centrated sulphuric acid drop by drop with shaking to a solution of the 

 amine in alcohol. On recrystallization from glacial acetic acid it was obtained 

 as bright-yellow leaflets, melting at about 205^0. The action of water on 

 this salt restored the amine. 



Diazoniicm Salts of 2-Nitro-i:-aininostilhene. 

 The diazonium sulphate may be obtained by the method of Sachs and 

 Hilpert {loc. cit.), or by the following method, which gives an equally good 

 Id:— 

 Ten grams of 2-nitro-4-aniinostilbene sulphate were finely powdered, and 



rr2i 



