Bayer Aktiengesellschaft

Werner Evertz

Karlfried Wedemeyer

Ferdinand Hagedorn

Wolfgang Kiel

Heinz U Blank

Wolfgang Schenk

The invention relates to a process for the preparation of anilines which are m-substituted by chlorine, by selective dehalogenation of more highly chlorinated anilines in an acid medium in the presence of noble metal catalysts and in the presence of optionally substituted phenols. The 3-chloro- or 3,5-dichloroanilines obtainable by the process according to the invention are known intermediate products, and can be used for the preparation of plant protection agents.

Process for preparation of anilines which are m-substituted by chlorine

An improved process for the preparation of an m-halogen-substituted aniline from a polyhalogen substituted aniline by the reaction of the aniline with hydrogen in an acid medium is disclosed wherein the process is carried out in the presence of hydrogen iodide and/or a compound which under the reaction conditions yields hydrogen iodide and in the presence of an optionally substituted phenol.

Process for the preparation of m-halogen-substituted anilines

An improved process for the preparation of fused 1,2,3-triazoles by reaction of an ortho-diaminoaryl with an ester of nitrous acid in a soluent or diluent is disclosed wherein the process is catalyzed by the use of a 1,2,3-triazole.

Process for the preparation of fused 1,2,3-triazoles

An improved process for the preparation of a sulphonic acid chloride of the formula ##STR1## wherein R.sup.1, R.sup.2 and R.sup.3 are identical or different and denote hydrogen, a lower alkyl radical or a cycloalkyl radical, halogen, aryl, aralkyl, aryl ether or a radical --SO.sub.2 Cl, --SO.sub.2 aryl, ##STR2## or wherein adjacent radicals R.sup.1 and R.sup.2 are linked to form a cycloaliphatic, aromatic or hetero-aromatic ring which is optionally substituted by a sulphonic acid chloride group by contacting an aromatic compound of the formula ##STR3## wherein R.sup.1, R.sup.2 and R.sup.3 of the above-mentioned meaning, with chlorosulphonic acid and thionyl chloride, the improvement residing in employing initially approximately stoichiometric amounts of aromatic compound and chlorosulphonic acid, effecting reaction of the aromatic compound and chlorosulphonic acid and thereafter contacting the reaction product with excess thionyl chloride.

Process for the preparation of sulphonic acid chlorides

Analines, meta-substituted by chlorine are prepared by reacting chloro-anilines having the formula ##STR1## wherein X.sup.1 and X.sup.2 are the same or different and represent chlorine, hydrogen or optionally substituted alkyl, aryl, aralkyl, alkoxy or aralkoxy, with one of the radicals X.sup.1 or X.sup.2 representing chlorine when 3-chloroanilines are being prepared and

Process for preparing 3-chloro- and 3,5-dichloro-anilines

A method of preparing a meta-chloroaniline by contacting a substituted aniline containing a chlorine substituent at other than a meta position and a chlorine substituent at the meta position with hydrogen in solution in an acid medium in the presence of a noble metal catalyst at elevated temperature and pressure. The aniline reactant can contain organo substituents on the ring. The product which results is either a 3-chloroaniline or a 3,5-dichloroaniline which similarly can contain organo substituents on the ring.

Process for the preparation of anilines meta-substituted by chlorine

Phenols, meta-substituted by halogen are prepared by reacting halogenophenols of the formula ##STR1## wherein X.sup.1 and X.sup.2 are identical or different and represent halogen, hydrogen or optionally substituted aryl or aralkyl, with at least one of the radicals X.sup.1 or

Growing community of inventors

Monheim, Germany

Werner Evertz