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: 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: 5-Arylidene hydantoins are produced by condensation of an aromatic aldehyde with hydantoin in the presence of at least one ammonium salt of an aliphatic or aromatic carboxylic acid. The desired 5-arylidene hydantoins are obtained in high yields.

Abstract: Tryptophane and tryptophane derivatives are purified by treating them in an inert solvent at a temperature between about 20.degree. C. and the boiling point of the mixture with a salt of dithionous acid. Preferably there is used as solvent a mixture of water and a lower aliphatic carboxylic acid. Normally a single treatment results in a pure, colorless, satisfactory product.

Abstract: 2-acetamidocinnamic acid and substituted 2-acetamidocinnamic acids are prepared by reacting glycine with an aromtic aldehyde in the presence of acetic anhydride and a tertiary amine and subsequently treating with water.

Abstract: Pure L-cystine is recovered from a mixture with other aminoacids by fractional crystallization in presence of acids and water from an alcoholic medium.

Abstract: Compounds are prepared of the formula ##STR1## where R' is a t-alkyl group having 4 to 18 carbon atoms, preferably t-butyl, t-amyl or t-octyl and R is a straight or branched chain alkyl group with 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms or an alkyl group substituted with one or more phenyl group or a halogen atom, particularly a chlorine atom, or a cycloalkyl group with 3 to 8 carbon atoms, particularly cyclopropyl, which can be substituted by one or more 1 to 3 carbon atom alkyl groups or one or more halogen atoms, preferably chlorine, or phenyl or naphthyl or a five membered heterocyclic group or such phenyl, naphthyl or heterocyclic group substituted by halogen atoms, nitro groups, alkyl or alkoxy with 1 to 5 carbon atoms by condensing in acid medium an acyl cyanide of the formulaR--CO--CN (II)where R is as defined above with either(a) a tertiary alcohol of the formulaHO--R' (III)in which R' is as defined above, or preferably(b) an alkene of the formula ##STR2## where R.sub.1 and R.sub.

Abstract: Compounds are prepared of the formula ##STR1## where R' is a t-alkyl group having 4 to 18 carbon atoms, preferably t-butyl, t-amyl or t-octyl and R is a straight or branched chain alkyl group with 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms or an alkyl group substituted with one or more phenyl groups or a halogen atom, particularly a chlorine atom, or a cycloalkyl group with 3 to 8 carbon atoms, particularly cyclopropyl, which can be substituted by one or more 1 to 3 carbon atom alkyl groups or one or more halogen atoms, preferably chlorine, or phenyl or naphthyl or a five membered heterocyclic group or such phenyl, naphthyl or heterocyclic group substituted by halogen atoms, nitro groups, alkyl or alkoxy with 1 to 5 carbon atoms by condensing in acid medium an acyl cyanide of the formulaR--CO--CN (II)where R is as defined above with either(a) a tertiary alcohol of the formulaHO--R' (III)in which R' is as defined above, or preferably(b) an alkene of the formula ##STR2## where R.sub.1 and R.sub.

Abstract: There are prepared thiazolidin-4-carbonitriles of the formula ##STR1## where R.sub.1 and R.sub.2 are alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, aralkyl or aralkyl or one of R.sub.1 and R.sub.2 is hydrogen or R.sub.1 and R.sub.2 are joined together with the adjacent ring carbon atom to form a ring as well as salts thereof. The compounds can be hydrolyzed to form cysteine.

Abstract: Thiazoline-(3) compounds of the formula ##STR1## in which R.sub.1, R.sub.2, R.sub.3, R.sub.4 and R.sub.5 are hydrogen, alkyl, alkenyl, cycloalkyl, cycloalkenyl, aryl, alkaryl or aralkyl or R.sub.1 and R.sub.2 or R.sub.3 and R.sub.4 or R.sub.3 and R.sub.5 or R.sub.4 and R.sub.5 are joined together to form a saturated or unsaturated ring are prepared by reacting (1) an oxo compound having a halogen atom on the carbon adjacent to the carbonyl group and having the formula ##STR2## where X is halogen, (2) an oxo compound of the formula ##STR3## (3) a metal or ammonium sulfide and (4) ammonia.

Abstract: Penicillamine or a homolog thereof is obtained by reacting a 2-disubstituted-5,5-alkyl-thiazolidine nitrile, alkyl having 1 to 6 carbon atoms, with a mineral acid in a two-stage proceeding wherein in the first stage relatively low temperatures and a relatively high concentration of the mineral acid are employed while in the second stage the concentration of the acid is relatively low and the temperatures are relatively high, the term "relatively" referring to the relationship of said two stages of the reaction with mineral acid.

Abstract: Organic basic nitrogen compounds are formylated in the presence of acetic anhydride by adding the nitrogen compound as a salt and carrying out the formylation with an alkali or ammonium formate in an organic solvent having limited miscibility with water.

Abstract: D,L-penicillamine is separated into its antipodes employing optically active threo-1-(p-nitrophenyl)-2-aminopropanediol-1,3.

Abstract: D,L-penicillamine is converted to D-penicillamine with the aid of 1-pseudonorephedrine.

Abstract: Penicillamine or a homolog thereof is obtained by reacting a 2-disubstituted-5,5-alkyl-thiazolidine nitrile, alkyl having 1 to 6 carbon atoms, with a mineral acid in a two-stage proceeding wherein in the first stage relatively low temperatures and a relatively high concentration of the mineral acid are employed while in the second stage the concentration of the acid is relatively low and the temperatures are relatively high, the term "relatively" referring to the relationship of said two stages of the reaction with mineral acid.

Abstract: 2 AND 5 SUBSTITUTED THIAZOLINE-(3) COMPOUNDS OF THE FORMULA: ##EQU1## in which R.sub.1, R.sub.2, and R.sub.3 and R.sub.4 are the same or different, R.sub.1 and R.sub.2 are straight or branched chain lower alkyl, alkenyl or aralkyl groups or together are a straight or branched chain alkylene or ethylenically unsaturated divalent aliphatic hydrocarbon group which joins with the adjacent carbon atom to form a ring and R.sub.3 and R.sub.4 are similarly defined except R.sub.3 can also be hydrogen by reaching a 2,2' dioxodisulfide of the formula ##EQU2## with an oxo compound of the formula ##EQU3## and with ammonia and hydrogen sulfide in the presence of an amine and an ammonium salt.