Basf Aktiengesellschaft

Fritz Brunnmueller

Michael Kroener

Rolf Schneider

Friedrich Linhart

Christian Dudeck

Karlheinz Stecher

Heinrich Hartmann

Hans Diem

Werner Fliege

Wolfgang Habermann

Joachim Kranz

Gunter Lehmann

Harry Distler

Helmut Knittel

Bernd Meissner

Klaus Pfitzner

Albrecht Aicher

Michael Kroner

Hans Haas

Hans Mueller

Waldemar Koehler

Karl-Ludwig Hock

Hans Diehm

Berthold Mueller

Ubbo V Oehsen

Reaction products of hydrogen cyanide are prepared by a process in which hydrogen cyanide prepared in a conventional manner by pyrolysis at from 250.degree. to 650.degree. C. over a solid under from 5 to 200 mbar is cooled to a temperature of from 200.degree. to -10.degree. C. together with the other pyrolysis products, the hydrogen cyanide is then fed to a chemisorption reaction with a base or with a carbonyl compound, and the reaction products of hydrogen cyanide which are formed therein are removed from the system and brought to atmospheric pressure. In this process, the handling of large amounts of hydrogen cyanide is avoided.

Preparation of the reaction products of hydrogen cyanide

A process for the thermolytic cleavage of formamide to give hydrocyanic acid and water over alumina or alumina/silica moldings subjected to final sintering or over high temperature corrosion-resistant stainless steel packings in the presence of atmospheric oxygen possesses, in particular, high HCN selectively and a high formamide conversion.

Cleavage of formamide to give hydrocyanic acid and water

Novel 2-aminopyrazines and processes for the preparation of 2-aminopyrazines and pyrazines by reaction of an .alpha.-iminodiacetonitrile (a) with a hydrogen halide or (b) with an alcohol or a thioalcohol and a hydrogen halide or (c) with an alcohol or a thioalcohol in the presence of an alkali metal compound and/of an alkaline earth metal compound. The 2-aminopyrazines and pyrazines obtainable by the process of the invention are useful starting materials for the preparation of dyes, fungicides, bactericides, textile assistants, scents, folic acid derivatives, flavorings, and active ingredients in crop protection and drugs.

Preparation of 2-aminopyrazines and pyrazines

Linear, basic polymer powders which contain units of the formula ##STR1## and have a Fikentscher K value of from 10 to 200 are prepared by eliminating the formyl groups from N-vinylformamide polymer powders with a gaseous hydrogen halide in the presence of not more than 5% by weight, based on the polymer used, of water.

Preparation of linear, basic polymer powders

Novel 2-aminopyrazines and processes for the preparation of 2-aminopyrazines and pyrazines by reaction of an .alpha.-iminodiacetonitrile (a) with a hydrogen halide or (b) with an alcohol or a thioalcohol and a hydrogen halide or (c) with an alcohol or a thioalcohol in the presence of an alkali metal compound and/or an alkaline earth metal compound. The 2-aminopyrazines and pyrazines obtainable by the process of the invention are useful starting materials for the preparation of dyes, fungicides, bactericides, textile assistants, scents, folic acid derivatives, flavorings, and active ingredients in crop protection and drugs.

2-Aminopyrazines and the preparation of 2-aminopyrazines and pyrazines

Novel .alpha.-iminodiacetonitriles are prepared by a process in which an aldehyde-cyanohydrin or a haloacetonitrile is reacted with an aminonitrile, the reaction being carried out in the presence of a lower alkanol in the case of the preparation of symmetric .alpha.-iminodiacetonitriles, and in the presence of an auxiliary base in the case of the preparation employing a haloacetonitrile. The .alpha.-iminodiacetonitriles obtainable by the process of the invention are useful starting materials for the preparation of dyes, fungicides, bactericides, herbicides, textile assistants, anticorrosion agents, complex-forming agents, stabilizers in electroplating baths and inhibitors for antifreezes.

.alpha.-iminodiacetonitriles and their preparation

Blue iron hexacyanoferrate-III pigments (I) are prepared by anodic oxidation of metallic iron in hydrogen cyanide, or a reaction medium containing hydrogen cyanide, at pH&lt;7 and at an anode potential of .ltoreq.0.76 V (measured against a standard hydrogen electrode) to complex iron-II hexacyanoferrate-II compounds (II), which are then oxidized to (I) in a conventional manner. The oxidation of (II) is advantageously carried out with air or oxygen at pH 0-4 and at from 70 to 95.degree. C., but can also be carried out at pH&gt;8. The process gives readily dispersible pigments (I) which are of high color strength and give brilliant, glossy colorations.

Preparation of blue iron hexacyanoferrate-III pigments, and the pigments

Linear basic polymers containing, as characteristic components, from 90 to 10 mole % of copolymerized units of the formula ##STR1## and from 10 to 90 mole % of copolymerized units of the formula ##STR2## are obtained by polymerizing the compound of the formula CH.sub.2 .dbd.CH--NH--CHO (N-vinylformamide) to a polyvinylformamide in the presence of a free radical polymerization initiator and splitting off the formyl group from the resulting polymer at from 20.degree. to 200.degree. in the presence of an acid or base. The reaction products are used as retention agents, drainage assistants and flocculants in papermaking.

Linear basic polymers, their preparation and their use

3-Alkyl-buten-1-als are prepared by oxidative dehydrogenation of 3-alkyl-buten-1-ols in the presence of a silver catalyst, of a particular total thickness, comprising 2 or more layers each of a particular weight and containing particles of a particular size. The products are starting materials for the manufacture of dyes, pesticides, drugs, plastics, naturally occurring materials and scents.

Preparation of 3-alkyl-buten-1-als

Formaldehyde is manufactured by oxidative dehydrogenation of methanol in the presence of a silver catalyst and of certain amounts of steam and formaldehyde, some formaldehyde and a part of the water being withdrawn from the reaction mixture and recycled. The formaldehyde manufactured by the process may be used as a disinfectant, tanning agent, reducing agent and starting material for the manufacture of synthetic resin, adhesives and plastics.

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Limburgerhof, Germany

Fritz Brunnmueller