Abstract: The present invention is aimed at a process for the preparation of compounds of the general formula (I). The objective process is in this case based on the Michael reaction of compounds of the general formula (III) with compounds of the general formula (IV), with subsequent hydrogenation and cyclization of the intermediates of the formula (II) obtained.

Abstract: The present invention is directed to a process for preparing ?-amino-?-hydroxycarboxamides. The process works with epoxycarboxamides of the formula 2 which are reacted with ammonia or other amines.

Abstract: The present invention is aimed at a process for the preparation of compounds of the general formula (I). The objective process is in this case based on the Michael reaction of compounds of the general formula (III) with compounds of the general formula (IV), with subsequent hydrogenation and cyclization of the intermediates of the formula (II) obtained.

Abstract: The present invention is directed to a process for preparing ?-amino-?-hydroxycarboxamides. The process works with epoxycarboxamides of the formula 2 which are reacted with ammonia or other amines.

Abstract: The present invention is directed to a process for preparing ?-amino-?-hydroxycarboxamides. The process works with epoxycarboxamides of the formula 2 which are reacted with ammonia or other amines.

Abstract: Process for the production of 2,5-diketopiperazines of general formula I, 1

Abstract: The present invention is directed towards compounds of the general formula (I) (I) are important intermediates for the preparation of pharmaceuticals. Further intermediates, process for the preparation of (I) and use thereof.

Abstract: The present invention relates to a process for the preparation of &ggr;-lactams of the general formula I The invention relates also to novel advantageous intermediates of the general formulae V, IV and II and their salts and their use. The compounds of the general formula I are obtained by cyclising compounds of the general formula II which can be prepared from the intermediate compounds V.

Abstract: 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).

Abstract: The present invention relates to a process for the preparation of &ggr;-lactams of the general formula I 1

Abstract: The present invention is directed towards compounds of the general formula (I) 1

Abstract: The present invention relates to a process for the preparation of &ggr;-lactams of the general formula I 1

Abstract: The present invention relates to a process for the preparation of &ggr;-lactams of the general formula I The invention relates also to novel advantageous intermediates of the general formulae V, IV and II and their salts and their use. The compounds of the general formula I are obtained by cyclising compounds of the general formula II which can be prepared from the intermediate compounds V.

Abstract: 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.

Abstract: 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.

Abstract: With known methods of racemizing N-acetyl-D(L)-.alpha.-amino carboxylic acids in the non-aqueous state by heating them to temperatures above room temperatures, significant quantities of by-products are formed, especially acetyl dipeptides. By converting at least a proportion of the N-acetyl-D(L)-.alpha.-amino carboxylic acids to corresponding N-acetyl-D(L)-.alpha.-amino carboxylic acid salts before or during the heating, it is possible to increase the sojourn time of the educt which is to be racemized at higher temperatures without any evident increase in the quantity of by-product formed (in particular acetylated dipeptides). Also disclosed is the production of optically active amino acids by enzymatic splitting of racemic compounds.

Abstract: The invention concerns a method of producing oxazolidinones of formula (I), wherein R.sup.1 -R.sup.5 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.degree. 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 .alpha.-selective production of esters of formula (V) and amides of general formula (VII).

Abstract: The invention concerns a method of producing L-aspartyl-D-alanine-N-(thietane-3-yl) amides of general formula I by reacting D-alanine-thietane amides of general formula II with oxazolidinone compounds of general formula III in an inert organic solvent, wherein R.sup.1 stands for H or a selectively separable protective group, R.sup.2 -R.sup.5 independently of one another, are identical or different and stand for H or linear or branched C.sub.1 -C.sub.4 -alkyl, and R.sup.6 and R.sup.7, independently of each other, are identical or different and stand for H, linear or branched C.sub.1 -C.sub.4 -alkyl, aryl or a group which activates the carbonyl group.

Abstract: The invention relates to a process for removing amino acids and/or aminosulphonic acids from preferably aqueous solutions which contain these as impurities by adsorbing the amino acids on zeolites. Solutions to which the process according to the invention can be applied are produced, for example, from the industrial synthesis of oligopeptides in which the amino acids serving as starting materials are always present in solution, sometimes to a not inconsiderable residual concentration, together with the desired end product.

Abstract: Novel a-acyl dipeptides of the formula:R.sup.2 --NH--CHR.sup.1 --O--ASin which AS, R.sup.1 and R.sup.2 have certain, more precisely defined meanings. These N-acyl dipeptides are more stable under conditions of sterilization (121.degree. C.) than corresponding, non-acylated dipeptides. On the other hand, they are cleaved more rapidly and more completely at the peptide bond in the living organism than the cleavage of the acyl group from simple N-acyl amino acids takes place. They can therefore be used with advantage as a source for the carbon terminal amino acid in mixtures and solutions for artificial nutrition or in culture media for cell cultures.