Abstract:
A process for the preparation of 2-thionoxazolidone-5 and derivatives thereof is disclosed wherein tertiary alkyl esters of secondary amino carboxylic acid or the N-thiocarbonyl chloride of an Alpha -secondary aminocarboxylic acid is subjected to the action of a proton yielding acid. The compounds produced by the process of this invention are useful as amino acid derivatives in the synthesis of peptides.
Abstract:
A process for preparing aspartyl Alpha -amino acid lower alkyl esters is disclosed, wherein an N-protected aspartic acid anhdyride is reacted with an Alpha -amino acid lower alkyl ester at a temperature of about -10 to +50 *C, and at a pH of 4-12, in an aqueous solvent. After the reaction, the N-protective group is removed to produce the desired aspartyl Alpha -amino acid lower alkyl ester which has a peptide linkage. Many of the products produced by the present invention are useful as sweetening agents, as well as starting materials in the synthesis of polypeptides, e.g. gastrine.
Abstract:
A process for preparing optically active methionine, methionine nitrile, and methionine amide is disclosed. A mixture of L- and D-methionine nitrile is at least partially converted to a salt of optically active Alpha -phenoxypropionic acid, and the resulting salt is subjected to optical separation by crystallization. The resultant optically active methionine nitrile may be converted into methionine or methionine amide. Optically active methionine or methionine amide is useful as a food and feed supplement.