Patent ID: 6916947

Claim:
A method of producing an amino acid, comprising: a) reacting a halogenated carboxylic acid ester with a metal cyanate and an alcohol at a temperature of between 80° C. and 200° C., to produce a urethane carbonic acid, wherein: i) said metal cyanate is placed in an aprotic, polar, organic solvent to form a solution; ii) said alcohol and halogenated carboxylic acid ester are added to said solution in a continuous manner; and b) producing said amino acid by acidic saponification of said urethane carbonic acid, wherein said halogenated carboxylic acid ester is a dicarboxylic acid diester with the structure of formula (II) wherein: n is a whole number from 0 to 10, R is a (C 1 -C 8 ) alkyl, R′ and R″ are each independently selected from: H; (C 1 -C 8 ) alkyl; (C 1 -C 8 ) acyl, (C 3 -C 8 ) cycloalkyl; (C 6 -C 18 ) aryl; (C 7 -C 19 ) aralkyl; (C 3 -C 18 ) heteroaryl; (C 4 -C 19 ) heteroaralkyl; ((C 1 -C 8 ) alkyl) 1-3 -(C 3 -C 8 ) cycloalkyl; ((C 1 -C 8 ) alkyl) 1-3 -(C 6 -C 18 ) aryl; and ((C 1 -C 8 ) alkyl) 1-3 -(C 3 -C 18 ) heteroaryl; and Hal signifies chlorine or bromine.