Abstract: Halogen thiophene carboxylic acid derivatives of the General Formula ##STR1## in which Hal signifies chlorine or bromine, n the number 2 or 3, * signifies either an enantiomer or a racemate in the case of different R.sup.2 and R.sup.3 groups,R.sup.1 stands for hydrogen or an alkyl group,R.sup.2 stands for hydrogen, an alkyl group which can optionally be substituted by hydroxy-, carboxy-, alkoxy- or alkoxycarbonyl, mercapto- or alkylmercapto- or benzylmercapto, for an aryl group or aralkyl group, wherein the ring system can optionally be substituted with fluorine, chlorine or bromine atoms, for a cycloalkyl group or a cycloalkyl-methyl group,R.sup.3 stands for hydrogen, an alkyl group, an alkenyl or alkynyl group or, optionally, R.sup.1 and R.sup.3 or R.sup.2 and R.sup.3 together can form an alkylene bridge in which one CH.sup.2 unit can optionally be substituted by NR.sup.1, O or S,Y signifies OH, OR.sup.4 or NR.sup.5 R.sup.6,in whichR.sup.

Abstract: A method for the removal of water or aqueous liquids from the sump of an underground cavity, especially a cavern, is based on providing a process in which a water-miscible organic liquid is added to the sump, and then the mixture formed in this way is extracted from the cavity.

Abstract: Thin-layer chromatography is employed to separate enantiomers of the general formula, ##STR1## in which C* represents an asymmetric center and the substituents R.sup.1, R.sup.2, and R.sup.3 are such that they supply the structural element ##STR2## for .alpha.-amino- or .alpha.-iminocarboxylic acids, particularly the well-known .alpha.-amino- or .alpha.-iminocarboxylic or for derivatives of such carboxylic acids, either of which contains no free thiol groups. In the thin-layer chromatographic separation operation a TLC plate is used which is coated with silica gel hydrophobicized by a silane derivative and which is further impregnated with an ionic compound of a divalent transition metal and a chiral selector. The mobile phase employed is a ternary mixture of a water-miscible alkanol, such as methanol, water, and acetonitrile, or a quaternary mixture of the latter ternary mixture to which a water-miscible cyclic ether, such as tetrahydrofuran, has been added.

Abstract: The separation of L-leucine and L-isoleucine in aminoacid mixtures containing at least 30 weight percent L-leucine, at most 70 weight percent L-isoleucine and at most 40 weight percent of other aminoacids is accomplished by acetylating the mixture, precipitating the acetylation product by acidification, subjecting the aqueous solution to a saponification by an L-aminoacid acylase until 25 to 95% of the N-acetyl-L-leucine is saponified, crystallizing pure L-leucine from the saponification mixture and separating it off, isolating N-acetyl-L-isoleucine from the mother liquor and saponifying it in known manner to the free aminoacid and isolating the free aminoacid.

Abstract: Pure L-leucine is obtained from an aminoacid mixture which contains at least 45 weight percent L-leucine, at most 40 weight percent L-isoleucine and at most 25 weight percent of other aminoacids by acetylating the mixture, precipitating the acetylation product by acidification, subjecting the acetylation product to a saponification by an L-aminoacid acylate until 30 to 95% of the N-acetyl-L-leucine employed is saponified and isolating the L-leucine from the saponification mixture.

Abstract: The subject matter of the invention is a process for the recovery of S-(carboxymethyl)-(R)-cysteine and S-(carboxymethyl)-(S)-cysteine from a mixture of the two enantiomers. The mixture to be separated is dissolved in water in the presence of sufficient ammonia that the ammonium salt solution formed has a pH between 6 and 9. Then there is brought about in the solution of ammonium salt a state of supersaturation by the addition of seeding crystals of the ammonium salt of one of the two enantiomers, insofar as the starting material contains one of the two enantiomers in excess, the ammonium salt of this enantiomer, the ammonium salt of one of the two enantiomers is brought to crystallization and separated off. Subsequently by addition of seeding crystals of the ammonium salt of the other enantiomers to the remaining mother liquor the ammonium salt of this enantiomer is likewise brought to crystallization and separated off.

Abstract: There are prepared 1-amino-2-mercapto-2-methylpropyl phosphonic acid or 1-amino-2-mercapto-2-methylpropyl alkylphosphinic acids of the formula ##STR1## in which Y is hydroxy or an alkyl group by reacting thiazoline-(3) with a phosphonic acid dialkyl ester or an alkylphosphinic acid alkyl ester and then hydrolytically splitting the thiazolidinyl phosphonic acid dialkyl ester or thiazolidinyl alkylphosphinic acid alkyl ester. The thiazolidinyl compounds are new compounds. The 1-amino-2-mercapto-2-methylpropyl phosphonic acid and the 1-amino-2-mercapto-2-methylpropyl alkylphosphinic acids are needed for pharmaceutical purposes.

Abstract: There are prepared specific .alpha.-aminocarboxylic acids or their methyl, ethyl, or benzyl esters in which the .alpha.-amino group is substituted by a 3-cyanopropanoyl group. The compounds are useful for producing the corresponding derivatives of 4-aminobutyramide ("Gabamide") by catalytic hydrogenation of the cyano group.

Abstract: L-proline is produced from the methyl or ethyl ester of L-pyroglutamic acid by reacting this with at least twice the molar amount of phosgene to form the corresponding 1-chlorocarbonyl-5,5-dichloroproline ester, producing the corresponding 2-chloro-1-chlorocarbonyl-pyrrolin-(2)-carboxylic acid ester-(5) therefrom by splitting off hydrogen chloride, catalytically hydrogenating the pyrrolin-(2) compound to the corresponding N-chlorocarbonyl-proline ester and hydrolyzing the latter with acid to form L-proline.

Abstract: The invention is directed to optically active proline derivative of the general formula: ##STR1## in which X is a hydrogen atom or a hydroxyl group and R is a hydrogen atom, an unsubstituted or alkyl group substituted phenyl group or a straight chain or branched alkyl group having 1 to 20 carbon atoms and a process for its production by reacting an enantiomerically pure proline or 4-hydroxy-proline as a solution in an alkanol having 1 to 4 carbon atoms with 0.9 to 2 times the molar amount of an alkali metal alcoholate corresponding to the alkanol and 1 to 3 times the molar amount of an epoxide of the general formula ##STR2## in which R is as defined above. The optically active proline derivative of general formula (I) can be used in the form of metal ion chelate complexes as the chiral stationary phase in the separation of enantiomers by means of liquid chromatography.

Abstract: Aqueous solutions of sodium salts of .alpha.-aminocarboxylic acids practically free of foreign salts are produced by saponifying the corresponding hydantoin at a temperature between 110.degree. C. and 180.degree. C. with a mixture, in each case based on the hydantoin, of 1 equivalent of sodium hydroxide and 2 equivalents of calcium oxide or hydroxide, separating off the precipitated calcium carbonate after the end of the saponification and concentrating the aqueous sodium salt solution remaining to drive off the ammonia contained therein.

Abstract: To separate the racemate (R,S)-cysteine, the racemate is condensed in an inert solvent with an enantiomerically enantiomeric monosaccharide of the group of aldoses having 4 to 7 carbon atoms to form the corresponding 2-substituted thiazolidin-4-carboxylic acid and the mixture of diastereomers obtained separated from each other. Subsequently, the isolated unitary diastereomers are reacted in an inert solvent with a carbonyl reagent to split the ring and the enantiomerically pure cysteine in each case is isolated as such or as the corresponding cystine.

Abstract: There are prepared specific .alpha.-aminocarboxylic acids or their methyl, ethyl, or benzyl esters in which the .alpha.-amino group is substituted by a 3-cyanopropanoyl group. The compounds are useful for producing the corresponding derivatives of 4-aminobutyramide ("Gabamide") by catalytic hydrogenation of the cyano group.

Abstract: There is described the resolution of the racemate S-(carboxymethyl)-(RS)-cysteine. It is carried out by means of the optical isomers of 2-amino-1-phenyl-propan-1-ol. This process makes it possible to obtain in a simple manner S-(carboxymethyl)-(R)-cysteine which is important for pharmaceutical purposes and is made from synthetically produced cysteine.

Abstract: There is described the resolution of the racemate (1RS,2SR)-2-amino-1-phenyl-propan-1-ol. It is carried out by means of the optical isomers of S-(carboxymethyl)-cysteine.

Abstract: There are produced thiazoline-(3) compounds which optionally are substituted or unsubstituted in the 2 and/or 5 positions by reaction of oxo compounds with a metal sulfides, ammonia and oxo compounds which are substituted by halogen in the position adjacent to the oxo group. In this process a mixture of oxo compounds, metal sulfides and ammonia is present and the halogen substituted oxo compound is introduced into the mixture. By using in this manner of mixing, high yields are obtained in a relatively short period of time.

Abstract: There is described the resolution of the racemate S-(carboxymethyl)-(RS)-cysteine. It is carried out by means of the optical isomers of 1-phenyl-ethylamine. This process makes it possible to obtain in a simple manner S-(carboxymethyl)-(R)-cysteine which is important for pharmaceutical purposes and is made from synthetically produced cysteine.

Abstract: Aqueous sodium methioninate solutions having a low content of sodium carbonate can be recovered from the crude hydrolysis mixture resulting from the saponification of 5-(.beta.-methylmercaptoethyl)hydantoin with 1.1 to 6 equivalents of sodium hydroxide and/or sodium carbonate by cooling the crude hydrolysis mixture to a temperature below 10.degree. C., separating off the precipitated sodium carbonate and concentrating the sodium methioninate solution remaining to 40 to 65 weight percent.

Abstract: Aqueous sodium methioninate solutions having a low content of sodium carbonate can be recovered from the crude hydrolysis mixture resulting from the saponification of 5-(.beta.-methylmercaptoethyl)-hydantoin with 1.1 to 6 equivalents of sodium hydroxide and/or sodium carbonate by distilling off the water from the crude hydrolysis mixture until the sodium methioninate content is 40 to 65 weight percent, and after cooling to at most room temperature separating off the precipitated sodium carbonate.

Abstract: 4-aminobutyramide hydrochloride is produced by saponifying 4-(benzylamino)-or-4-(dibenzylamino)-butyronitrile to the corresponding substituted 4-aminobutyramide and subjecting this in the form of the hydrochloride in the presence of an inert solvent and a platinum metal catalyst to a hydrogenation treatment whereby the benzyl group or the two benzyl groups are split off.