Haarmann & Reimer Gmbh

Bayer Aktiengesellschaft

Haarmann & Reimer Gesellschaft MIT Beschrankter Haftung

Reiner Molleken

Kurt Bauer

Helmut Fiege

Karlfried Wedemeyer

Alfred Krempel

Rudolf Hopp

Fritz Exner

Mixtures of 2- and 4-hydroxybenzyl alcohol with high contents of 4-hydroxybenzyl alcohol are obtained by a process comprising reacting phenol with paraformaldehyde in the presence of a compound which exhibits two or more tertiary nitrogen atoms per molecule and a pK.sub.a value of .gtoreq.6.5 (measured at 20.degree. C. in water).

Process for the preparation of a mixture of 2- and 4-hydroxybenzyl

Mixtures of 2- and 4-hydroxybenzyl alcohol with high contents of 4-hydroxybenzyl alcohol are obtained by a process comprising reacting phenol and paraformaldehyde in the presence of a strongly basic catalyst and a polyalkylene polyether.

Process for the preparation of a mixture of 2-and 4-hydroxybenzyl alcohol

Novel process for the preparation of an arylglyoxylic acid compound, e.g., phenylglyoxylic acid, which comprises oxidizing an .alpha.-hydroxyarylacetic acid, e.g., mandelic acid, of the formula ##STR1## in which m is 1, 2 or 3,

Process for the preparation of arylglyoxylic acids

A process for the preparation of pure 2-hydroxybenzyl alcohol, pure 4-hydroxybenzyl alcohol or a mixture of both hydroxybenzyl alcohols by reacting phenol and formaldehyde in the presence of a basic catalyst and subjecting the resulting reaction mixture to an at least 2-stage countercurrent extraction in a solvent system of water/organic solvent which is water-immiscible or water-miscible only to a limited extent.

Process for the preparation of pure 2-hydroxybenzyl alcohol, pure

Process for the preparation of 3,4-methylenedioxymandelic acid, wherein glyoxylic acid is reacted with 1,2-methylenedioxybenzene in a strongly acid medium.

Process for the preparation of 3,4-methylenedioxymandelic acid

The invention concerns a new process for the production of 2-alkoxy-4-propen-1-yl phenols of the formula ##STR1## in which R represents the methyl or ethyl radical wherein 2-alkoxy phenols of the formula ##STR2## in which R is as defined above, are initially condensed with propionaldehyde in the presence of acid catalysts, and the resulting condensation product is subsequently split by heating in the presence of a basic catalyst to form the phenols of formula I.

Process for the production of 2-alkoxy-4-propen-1-yl-phenols

Salicylaldehyde and other hydroxybenzaldehydes are prepared by oxydation of a hydroxybenzyl alcohol in the presence of a platinum metal catalyst and lead, silver, tellurium or tin or compounds thereof as activator.

Process for the preparation of hydroxybenzaldehydes

The invention concerns new 2-alkoxy-4-alkenyl phenols of the formula ##STR1## wherein R.sub.1 is methyl or ethyl and

Process for the production of 2-alkoxy-4-alkenyl phenols

The invention relates to a new process for the production of anethole (4-methoxy propen-1-yl benzene), wherein anisole is condensed with propionaldehyde in the presence of an acid catalyst and the resulting condensation product is subsequently split in the presence of an acid at a temperature in the range from 100.degree. to 300.degree. C.

Process for the production of anethole

Glyoxylic acid is selectively extracted from its aqueous mixture with glyoxal by means of aliphatic or cycloaliphatic alcohol containing about 4 to 8 carbon atoms, a ketone containing about 4 to 8 carbon atoms, and an ester of an aliphatic carboxylic acid and aliphatic alcohol each containing up to about 6 carbon atoms, the esters containing a total of about 3 to 8 carbon atoms, allowing the mixture to stratify and separating the solvent layer enriched in glyoxylic acid.

Growing community of inventors

Golmbach, Germany

Reiner Molleken