EXPERIMENTAL. 33 



The combined alcoholic solutions from fractions II and III, which con- 

 tained the proline, were evaporated to dry ness under reduced pressure, and 

 the residue extracted with boiling alcohol, in which 2.3 grams did not dis- 

 solve. The solution filtered from this was again evaporated to dryness 

 under reduced pressure, the residue dissolved in water, and the copper salts 

 prepared by boiling for an hour with an excess of copper hydroxide. The 

 deep blue solution was evaporated to dryness under reduced pressure, and 

 the residue boiled with absolute alcohol, which dissolved the /-proline copper 

 salt. The residue of racemic copper salt, insoluble in alcohol, was dissolved 

 in water and the solution concentrated. Of racemic proline copper 2.41 

 grams were obtained, equivalent to 1.69 grams of -proline. 



Water: 0.3190 gram substance, air-dried, lost 0.0353 gram H 2 O at 110. 

 Copper : 0.2827 gram substance, dried at 110, gave 0.0766 gram CuO. 

 Calculated for C 10 H 16 O 4 N 2 Cu. 2 H 2 O, H 2 O n.oo p. ct. ; found, H 2 O 11.07 P- ct. 

 Calculated for C 10 H 16 O 4 N 2 Cu, Cu 21.79 P- c ^ ; found, Cu 21.65 P- ct. 



The alcoholic solution of the copper salt of the /-proline was evaporated 

 to dryness under reduced pressure. The dried residue weighed 8.24 grams, 

 equivalent to 6.5 grams of /-proline. 



For identification a small portion was freed from copper with hydrogen 

 sulphide, and the free proline converted into the phenylhydantoin, accord- 

 ing to the directions of Emil Fischer. 1 



The hydantoin melted sharply at 143 and gave the following analysis : 



Carbon and hydrogen : 0.2334 gm. substance gave 0.5676 gm. CO 2 and 0.1204 g m - H 2 O. 

 Nitrogen : 0.1373 gram substance gave NH 3 = 1.78 cc. HC1 (i cc. HC1 = o.oi gram N). 

 Calculated for C 12 H 12 O 2 N 2 , C 66.60, H 5.61, N 12.99 P- ct. ; found, C 66.32, H 5.73, N 

 12.96 p. ct. 



f Fraction IV. Temperature of bath up to 200. ") 

 { Pressure, 0.8 mm. Weight, 49.39 grams. j 



From fraction IV the ester of phenylalanine was removed in the usual 

 manner by shaking out with ether, and after freeing from ether the residual 

 ester was saponified by dissolving in concentrated hydrochloric acid and 

 evaporating on the water-bath. Of phenylalanine hydrochloride 12.12 

 grams were obtained, which is equivalent to 9.93 grams of phenylalanine. 

 For identification the hydrochloride was recrystallized from strong hydro- 

 chloric acid and converted into the free acid by evaporation with excess of 

 ammonia. When once recrystallized from water, it melted at 263 to 265. 



Carbon and hydrogen : 0.2962 gram substance, dried at 110, gave 0.7089 gram CO 2 and 



0.1801 gram H 2 O. 



Nitrogen : 0.1924 gram substance gave NH 3 = 1.65 cc. HC1 (i cc. HC1 = o.oi gram N). 

 Calculated for C 9 H U O 2 N, C 65.39, H 6.73, N 8.50 p. ct. ; found, C 65.27, H 6.76, N 



8.57 P- ct. 



Fischer, B., Zeitschrift fur physiologische Chemie, 1901, xxxm, p. 251. 

 3 



