130 THE SIMPLER NATURAL BASES 



The hydrochloride, C 8 H U N . HC1, is soluble in alcohol and melts at 

 217 ; with mercuric chloride a sparingly soluble crystalline compound 

 is formed. Other salts are the acid oxalate, C 8 H U N . C 2 H 2 O 4 , m.p. 1 8 1 ; 

 the normal oxalate, (C 8 H n N) 2 C 2 H 2 O 4 , m.p. 2 1 8 ; and ttizpicrate, C 8 H n N. 

 C 6 H 3 O 7 N 3 , tetragonal prisms, m.p. 171-174, readily soluble in warm 

 water. 



The benzoyl derivative, C 6 H 5 . CH 2 . CH 2 . NH . CO . C 6 H 5 , melts 

 at 114. 



p-Hydroxy-phenyl-ethylamine. 



Small quantities of this amine are most readily prepared by heat- 

 ing tyrosine under reduced pressure in test tubes dipping into a bath 

 of fusible metal at 260-270 ; the amine sublimes ; the yield is 

 50 per cent. (cf. F. Ehrlich and Pistschimuka [1912]). For the 

 isolation from complex mixtures such as are obtained in putrefaction, 

 the base can be precipitated with phosphotungstic acid, but the 

 phosphotungstate is rather soluble. On fractionation with silver and 

 baryta, the base is obtained as platinichloride from the lysine fraction. 

 A better way is to utilise its phenolic properties by washing its 

 solution in *5N sodium hydroxide with amyl alcohol, neutralising, add- 

 ing sodium carbonate and extracting the amine with amyl alcohol. 

 After distilling off the solvent with steam, the dibenzoyl derivative 

 is obtained by the Schotten-Baumann method. 



In sufficient quantity p-hydroxy-phenyl-ethylamine is best purified 

 by distillation ; it boils at 161-163 at 2 mm - an( * 175-181 at 8 mm. It 

 is also readily purified by crystallisation from boiling xylene in which 

 it is very sparingly soluble. It forms colourless hexagonal leaflets 

 melting at 161, soluble in 95 parts of water at 15 and in about 10 

 parts of boiling ethyl alcohol. The base is fairly soluble in amyl 

 alcohol, but hardly at all in ether or chloroform. It gives Millon's 

 and Morner's reaction for tyrosine, but no coloration with triketo- 

 hydrindene hydrate. 



The hydrochloride, C 8 H n ON . HC1, is very soluble in water and may 

 be crystallised from concentrated hydrochloric acid; m.p. 268. 



The phosphate, C 8 H n ON . H 3 PO 4 . i|H 2 O, forms white prisms, 

 readily soluble in water; m.p. 209-210. 



The picrate, C 8 H n ON . C 6 H 3 O 7 N 3 , forms short prisms; m.p. 200. 



The platinichloride, (C 8 H n ON) 2 HJ?tCl 6 , forms six-sided leaflets. 



The N-monobenzoyl derivative crystallises from alcohol in hexagonal 

 plates; m.p. 162. 



The dibenzoyl derivative, C 6 H 5 CO.O.C 6 H 4 .CH 2 CH 2 .NH.CO.C 6 H 5 , 



