摘要:
This invention relates to a process for the preparation of free L .alpha.-amino acids by the complete conversion of their D antipodes taken individually or possibly in racemic mixtures.The process according to the present invention is characterized in that the D antipodes of an ester of said .alpha.-amino acid is racemized in the presence of a chemical catalyst formed by at least one aromatic aldehyde corresponding to the general formula: ##STR1## wherein: Ar represents an aromatic ring optionally containing a heteroatom, such as nitrogen, andB represents a basic function,to produce a mixture in dynamic equilibrium of the two forms D and L of said ester, the ester which is present in the L form is hydrolyzed enzymatically and irreversibly to produce the corresponding stereostable L .alpha.-amino acid, said stages of chemical racemization and of enzymatic hydrolysis being carried out under identical reaction conditions, and the free L .alpha.-amino acid is recovered.
摘要:
The present invention relates to a process for the preparation of 2-thienylethylamine derivatives of general formula: ##STR1## as well as their acid addition salts, in which R represents a halogen atom and R.sub.1 represents a C.sub.1 -C.sub.4 alkyl group, characterized in that a thienylglycidic derivative of general formula: ##STR2## in which M represents an alkali metal atom or a fraction of an alkaline-earth metal atom, is reacted with a phenylglycine ester, optionally in the form of a strong acid salt, of general formula: ##STR3## in which R and R.sub.1 have the same meaning as above, in the presence of an alkali metal borchydride of general formula:X--Y IVin which X represents an alkali metal atom and Y represents a group of formula:--BH.sub.3 CN or --BH.sub.(4-w) Z.sub.win which Z represents a carboxylic acid residue and optionally in the presence of a C.sub.1 -C.sub.4 carboxylic acid, which gives the desired compound in the form of a free base which can be treated, if necessary, with an acid in order to obtain an addition salt of this compound.
摘要:
This invention relates to a process for the catalytic hydrolysis of an .alpha.-aminonitrile in the heterogeneous phase, and to polymeric resins having a catalytic activity for carrying out the present process.The process according to this invention is characterized in that said .alpha.-aminonitrile or one of the salts thereof is reacted in an aqueous medium, in the heterogeneous phase and in the presence of hydroxide ions on a polymeric resin which contains side chains carrying a carbonyl group, and which is insoluble in the aqueous basic medium.