Resolution of alkyl esters of DL-phenylalanine
AssigneeG. D. Searle & Co.
InventorPaul B. Sollman
Life of this patent
Estimating the term…
Abstract
Treatment of DL-phenylalanine alkyl esters with N-acyl-D-phenylalanines results in the formation of insoluble salts of the L-phenylalanine alkyl esters and N-acyl-D-phenylalanines. The salts are isolated and decomposed to afford the desired L-phenylalanine alkyl esters, which are important starting materials in the preparation of artificial sweetening agents.
Claims10
In a process for resolving alkyl esters of DL-phenylalanine, the step which comprises contacting a lower alkyl ester of DL-phenylalanine with N-(lower alkanoyl)-D-phenylalanine, wherein lower alkyl comprehends lower alkyl radicals having 1-4 carbon atoms inclusive and lower alkanoyl comprehends lower alkanoyl radicals having 1-8 carbon atoms inclusive.
A composition of matter which comprises a salt of the formula ##SPC1##
- wherein R.sub.1 is a lower alkyl radical having 1-4 carbon atoms inclusive and R.sub.2 is hydrogen or a lower alkyl radical having 1-7 carbon atoms inclusive.
A process for resolving an alkyl ester of DL-phenylalanine which comprises contacting a lower alkyl ester of DL-phenylalanine with an N-(lower alkanoyl)-D-phenylalanine;
- isolating the salt of the lower alkyl ester of L-phenylalanine and the N-(lower alkanoyl)-D-phenylalanine;
- and separating the lower alkyl ester of L-phenylalanine from the N-(lower alkanoyl)-D-phenylalanine.
In a process for obtaining a lower alkyl ester of D-phenylalanine from the corresponding lower alkyl ester of DL-phenylalanine, the step which comprises contacting a lower alkyl ester of DL-phenylalanine with N-(lower alkanoyl)-L-phenylalanine, wherein lower alkyl comprehends lower alkyl radicals having 1-4 carbon atoms inclusive and lower alkanoyl comprehends lower alkanoyl radicals having 1-8 carbon atoms inclusive.
Dependencies are inferred from the claim text.