Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Degussa Aktiengesellschaft

Paul Scherberich

Axel Kleemann

Heribert Offermanns

Gerd Schreyer

Friedrich Asinger

Wolf-Dieter Pfeifer

Werner Schwarze

Herbert Klenk

Jurgen Martens

Theodor Lussling

Karlheinz Drauz

Horst Weigel

Franz Effenberger

Horst Bethge

Alfred Maierhofer

Wolf D Pfeifer

Wolf Dieter Pfeifer

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.

Process for the production of L-proline

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.

Process for the production thiazolines-(3)

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.

Process for the production of 5-arylidene hydantoins (B)

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.

Process for the purification of tryptophane and derivatives of

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.

Process for the production of 2-acetamidocinnamic acid

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

Process for the recovery of pure L-cystine

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 formula

N-Substituted .alpha.-ketocarboxylic acid amides

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 formula

Process for the production of N-substituted .alpha.-ketocarboxylic acid

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.

Thiazolidin-4-carbonitrile

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.

Process for the production of thiazoline-(3) compounds

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.

Process of making penicillamine

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.

Process for formylation

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

Process for the resolution of D,L-penicillamine and salts formed during

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

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Dietzenbach, Germany

Paul Scherberich