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US 4,234,744 AGranted
Process for the production of aminoacid hydrochlorides/or diaminoacid dihydrochlorides
AssigneeDeutsche Gold- und Silber-Scheideanstalt vormals Roessler
InventorsFranz Effenberger, Karlheinz Drauz
Life of this patent
Estimating the term…
Abstract
Aminoacid hydrochlorides or diaminoacid dihydrochlorides are produced by first reacting a halocarboxylic acid ester with an alkali metal cyanate in the presence of an alcohol to form the corresponding mono- or diurethane and then saponifying this to the corresponding mono- or dihydrochloride. The new process is relatively versatile in its use and above all opens up an elegant synthesis route for lysine.
Claims14
A process for the production of an aminoacid hydrochlorides or a diaminoacide dihydrochlorides comprising reacting an ester of a halocarboxylic acid having the formula:
- ##STR2## in which Hal is chlorine or bromine, R is methyl or ethyl, R' is hydrogen or an alkyl group with 1 to 6 carbon atoms, n is one or a whole number between 3 and 5 inclusive and m is a whole number between 2 and 4 inclusive, in an aprotic solvent at a temperature between 80.degree. and 120.degree. C. with an alkali metal cyanate of the formula MeOCN in which Me is lithium, sodium or potassium, and methanol or ethanol and subsequently saponifying the alkoxycarbonylaminocarboxylic acid ester or bis-(alkoxycarbonylamino)-carboxylic acid ester with a mixture of equal parts of concentrated hydrochloric acid, 100 weight percent formic acid and water at reflux temperature.
Dependencies are inferred from the claim text.