摘要:
The invention concerns a method of producing oxazolidinones of formula (I), wherein R1-R5 have the meanings given in the description, by reacting cyclical anhydrides of formula (II) with carbonyl compounds of general formula (III) at temperatures between ambient temperature and approximately 150° C. The invention also concerns the production of the cyclical anhydrides of formula (II) by reacting N-protected aminodicarboxylic acids of formula (IV) with a dehydrating agent in situ. The invention further concerns the use of oxazolidinones of formula (I) for the &agr;-selective production of esters of formula (V) and amides of general formula (VII).
摘要:
A plant peptide amidase from the flavedo of oranges is known; this can be obtained only in small quantities and is seasonal. The proposed new enzymes are microbial peptide amidases which can be obtained from micro-organisms recovered from soil samples in a “double screening” and grown. These microbial peptide amidases are particularly useful for (a) the production of peptides and N-terminal-protected amino acids, (b) racemate splitting of N-protected amino acid amides, (c) obtaining non-proteinogenous D-amino acids, and (d) obtaining new N&agr;-protected D-amino acid amides.
摘要:
A process for the enantioselective epoxidation of C═C double bonds and use of the epoxides. The present invention provides a process for the enantioselective epoxidation of compounds of the formula I by means of a diastereomer and enantiomer enriched homopolyamino acid and an oxidizing agent. The epoxides prepared according to the invention are used as intermediates in organic syntheses.
摘要:
Highly concentrated aqueous L-Tryptophan and/or L-Threonine salt solutions are used to supplement mixed feeds with L-Tryptophan and/or L-Threonine. They can be metered easily and accurately, can be produced in a highly concentrated form with a content of between 30 and 70% and are storage stable to a surprisingly high degree (slight tendency to crystallize, no chemical decomposition, no racemization) even over a relatively long period of at least three months when outside temperatures are low.
摘要:
The invention is directed to a process for the preparation of lactams of Formula I. It is further directed to new advantageous intermediates of Formula II and the use thereof. By the cyclization of compounds of Formula II, compounds of Formula I are obtained.
摘要:
The disclosure relates to a process for obtaining optically active L-.alpha.-aminocarboxylic acids from the corresponding racemic D,L,.alpha.-aminocarboxylic acids. The following steps are involved: (a) the D,L,.alpha.-aminocarboxylic acids are acetylated; (b) the N-acetyl-L-.alpha.-aminocarboxylic acid present in the mixture of N-acetyl-D,L,.alpha.-aminocarboxylic acids thus obtained is broken down enzymatically into the L-.alpha.-aminocarboxylic acid; (c) the L-.alpha.-aminocarboxylic acid is separated from the mixture, a quantity of a solution of N-acetyl-D(L)-.alpha.-aminocarboxylic acids and a quantity of acetate equivalent to the L-.alpha.-aminocarboxylic acid being retained; and (d) the N-acetyl-D(L)-.alpha.-aminocarboxylic acid is racemized and recycled for enzymatic breakdown. Known extraction processes involving steps (a) to (d) have the disadvantage of producing large quantities of salt. Specifically, the processes are far removed from the ideal equation, according to which one hundred percent of the acetic anhydride and the D,L,.alpha.-aminocarboxylic acids are converted to L-.alpha.-aminocarboxylic acids and acetic acid. Adjusting the retained solution from step (c) in such a way as to obtain a solution consisting essentially of N-acetyl-D-(L)-.alpha.-aminocarboxylic acid salt and free acetic acid in equilibrium with acetate and free N-acetyl-D(L)-.alpha.-aminocarboxylic acid and from which acetic acid is extracted by distillation makes it surprisingly easy to feed the solution formed as "mother liquor" following separation of the L-.alpha.-aminocarboxylic acid in the circuit and to achieve a materials balance as close as possible to the ideal.
摘要:
A process for producing 2-[3(S)-amino-2-(R)-hydroxyl-4-phenyl butyl]-N-tert,butyl decahydro-(4aS,8aS)-isoquinoline-e(S)-carboxamide of the formula (I) via 3(S)-[lower alkoxy carbonyl amino, phenoxy carbonyl amino or benzyl oxycarbonyl amino]-2-hydroxy-4-phenyl butyric acid and process for producing said acid.
摘要:
A method of isolating 1-�N.sup.2 -((S)-ethoxycarbonyl)-3-phenylpropyl)-N.sup.6 -trifluoroacetyl!-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE). The solvent or solvent mixture used for the extraction is also a main constituent of the solvent or solvent mixture from which the crystallization takes place. High yield as well as good purity of the end product are obtained, without distillation. 1-�N.sup.2 -((S)-ethoxycarbonyl)-3-phenylpropyl)-N.sup.6 -trifluoroacetyl!-L-lysyl-L-proline (lisinopril (TFA) ethyl ester, LPE) is described as a precursor for producing an ACE inhibitor.