Phthaloyl-L-phenylalanine

MP 191° to 192,5°C, Two recrystallizations from aqueous ethanol gave the cinchonidine salt of the L-acid, MP 192,5° to 194°C. To the salt (2.9 g) in warm ethanol (50 ml) was added water (50 ml) and a slight excess (ca 10 ml) of N aqueous sodium hydroxide. The mixture was diluted with water, cooled, filtered from the precipitated base and the filtrate acidified with hydrochloric acid. Refluxing with 2 N ethanolic hydrogen chloride yielded p-nitro-N-phthaloyl-L-phenylalanine ethyl ester, according to U.S. Patent 3,032,585. 

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See also in sourсe #XX -- [ ]

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