Deutsche Gold- Und Silber-scheideanstalt Vormals Roessler

Hans B Wagner

Alfred Maierhofer

Theodor Lussling

Heribert Offermanns

Herbert Klenk

Herbert Tanner

Gerhard Pohl

Rudolf Fahnenstich

Horst Ferch

Gerd Eikelmann

Sven Peter Mannsfeld

Erich Liebetanz, Deceased

Sven-Peter Mannsfeld

Arno Pfeiffer

Arno Broll

The process described in Klenk U.S. Pat. No. 4,113,773 is improved by employing alkali metal cyanide in which at least half of the alkali metal cyanide has a particle size below 0.4 mm and the remainder has a particle size below 1.0 mm.

Process for the production of benzoyl cyanide (I)

Benzoyl cyanide is made from benzoyl chloride and an alkali metal cyanide in a two phase system comprising water and an inert organic solvent which has only slight miscibility with water in the presence of a tertiary amine and hydrogen cyanide.

Process for the production of benzoyl cyanide (IV)

Very pure S-carboxymethyl-L-cysteine is prepared by reacting L-cystine in liquid ammonia with metallic sodium to form the disodium salt of L-cysteine, evaporating the ammonia, reacting the disodium salt of L-cysteine with an aqueous solution of chloroacetic acid and precipitating the S-carboxymethyl-L-cysteine formed by acidifying the reaction mixture. There is employed 0.1 to 10 weight percent of a reducing agent based on the chloroacetic acid.

Process for the production of high purity S-carboxymethyl-L-cysteine

2-Hydroxy-4-methyl valeric acid and its salts are useful as sweeteners. The preferred sweeteners are the sodium and potassium salts.

Sweet material

Benzoyl cyanide is made by reacting benzoyl chloride with an alkali cyanide in the presence of a carboxylic acid nitrile and a copper (I) salt at a temperature of about 50.degree. to 160.degree. C.

In a continuous process 5-(.beta.-methylmercaptoethyl)-hydantoin is subjected to hydrolysis at an elevated temperature and elevated pressure in an aqueous solution of alkali carbonate or alkali bicarbonate or a mixture of these two compounds. The ammonia and carbon dioxide which form during the hydrolysis are removed and when the hydrolysis is complete the methionine is separated by means of carbon dioxide and the mother liquor is recirculated into the process after replenishing with fresh amounts of said hydantoin.

Continuous process for the manufacture of methionine

N-acetyl-L-methionine is prepared by reacting L-methionine with acetic anhydride in the presence of aqueous alkali at a temperature between 20.degree. and 60.degree. C. at a pH between 6.5 and 10. Preferably, there are used 1.05 to 1.70 moles of acetic anhydride per mole of L-methionine.

Process for the production of N-acetyl-L-methionine

There is provided a process for the production of firing stable yellow to red glaze mixtures for ceramic products containing as a color carrier cadmium sulfide and/or cadmium sulfoselenide, the glaze mixture consisting of 60 to 98 parts by weight of a base frit, 2 to 40 parts by weight of a color frit, and the customary amounts of suspension agents, in which the base frit can be any frit (known in itself) and the color frit consists of cadmium, sulfur and selenium containing compounds and a so-called base glass, which is composed of one or more known glaze frits. There is added to this color frit one or more glaze stable compounds in an amount of 25 to 95 weight % annealing carried out, at temperatures above 850.degree. C. and subsequently the color frit mixed with the base frit and suspension agent. The glaze stable compound is zirconium oxide, zirconium silicate, tin oxide, cerium oxide, aluminum oxide or titanium oxide.

Process for the production of firing stable yellow to red glaze mixtures

Aqueous carbon black compositions are made containing fluorine containing wetting agents to increase the stability to weather. The carbon black compositions are useful in mineral binder systems, for example for concrete, slate, clear concrete, asbestos concrete and exterior plaster formulations.

Carbon black preparation for use in mineral binder

3,6-BIS-(2-METHYLMERCAPTOETHYL)-2,5-PIPERAZINEDIONE IS PREPARED FROM 5-(2-METHYLMERCAPTOETHYL)-HYDANTOIN IN THE PRESENCE OF WATER AT 100.degree. TO 200.degree.C. at elevated pressure.

Process for the production of

Methionine is stabilized by adjusting the pH to the range from 3 to &lt;5. The source of the hydantoin is preferably 5-(beta-methylmercaptoethyl)-hydantoin.

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Bad Homburg, Germany

Hans B Wagner