Hoechst Aktiengesellschaft

Hans-Jurgen Arpe

Ernst I Leupold

Friedrich Wunder

Hans-Joachim Schmidt

Hansjorg Hey

Heinz Litterer

Klaus Eichler

Herbert Baltes

Horst Hachenberg

Lothar Schulz

Norbert Mayer

Helmut Schaum

Ernst-Gunther Schlosser

Albert Renken

The invention relates to a process for isomerizing monochlorotoluenes or dichlorotoluenes on a zirconium-containing zeolite catalyst of the Pentasil type. Catalysts of this type are distinguished by a particularly high activity coupled with a long service life. In particular, the invention relates to the preparation of a mixture 3-chlorotoluene and 4-chlorotoluene by isomerizing 2-chlorotoluene on zircoium-containing zeolite catalysts of the Pentasil type. The invention also relates to the preparation of a mixture of 2,5-dichlorotoluene and 3,4-dichlorotoluene by appropriate isomerization of 2,4-dichlorotoluene, and to the preparation of a mixture of 2,4-dichlorotoluene and 2,5-dichlorotoluene by appropriate isomerization of 3,4-dichlorotoluene.

Process for isomerizing monochlorotoluenes or dichlorotoluenes

The invention relates to a process for the isomerization of o-, m- or p-toluidine, or of a mixture of them, on a zirconium-containing zeolite catalyst of the pentasil type. Catalysts of this type are distinguished by particularly high activity and a long useful life. The invention particularly relates to the preparation of m-toluidine by isomerization of o- and/or p-toluidine on zirconium-containing zeolite catalysts of the pentasil type.

Process for the isomerization of o-, m- and/or p-toluidine

The invention relates to a process for preparing p-chlorotoluene and/or m-chlorotoluene by ring-chlorination of toluene by using the following two pages (a) and (b) when further processing the toluene chlorination product composed of mixed isomers:

Process for preparing p-chlorotoluene and/or m-chlorotoluene

The invention provides a process for the manufacture of o-toluidine and/or m-toluidine and/or p-toluidine, which comprises the two following steps (a) and (b): (a) treatment of a toluidine isomer mixture or of the not intended toluidine isomer or of one of the not intended toluidine isomers with an isomerization catalyst selected from the group of synthetic zeolites of the pentasil type, (b) isolation of the intended isomer or one of the intended isomers from the isomer mixture formed in step (a) by selective adsorption to a medium-pore or large-pore zeolite and subsequent desorption, furthermore discharge of the isolated isomer and recycling of the remaining isomer mixture to step (a).

Process for the manufacture of o-toluidine and/or m-toluidine and/or

The invention relates to a process for reacting RO--CH.sub.2 --OR formaldehyde acetals with carbon monoxide in the liquid phase on an acid organic ion exchange material as catalyst. The main products are ether-esters, RO--CH.sub.2 --COOR, of hydroxyacetic acid (glycolic acid).

Process for carbonylating formaldehyde acetals

Ethanol is manufactured by reaction of carbon monoxide with hydrogen on a supported rhodium catalyst containing as cocatalyst at least one of the elements zirconium, hafnium, lanthanum, platinum, chromium and mercury.

Process for the manufacture of ethanol from synthesis gas

Ethers of the hydroxypivalaldehyde RCH.sub.2 OCH.sub.2 C(CH.sub.3).sub.2 CHO are prepared by a catalytic isomerization of 5,5-dimethyl-1,3-dioxans at 250.degree. to 500.degree. C. The catalyst is obtained by way of calcination from silicon dioxide, at least one element of the third main group or subgroup in the form of its oxide or hydroxide and at least one alkali metal oxide or hydroxide.

Process for the manufacture of ethers of hydroxy-pivalaldehyde

Acetic acid, ethanol, acetaldehyde and possibly secondary products thereof are prepared by the catalytic reaction of carbon monoxide and hydrogen. The catalyst contains, applied onto a carrier, salts or complex compounds of rhodium with a valence below 3, halide ions and salts or complex compounds of magnesium.

Process for the manufacture of oxygen-containing carbon compounds from

Lower alkenes, especially ethylene, are produced from methanol and/or dimethyl ether in the presence of aluminum silicate catalysts containing manganese and possibly further co-catalysts.

Process for the manufacture of lower alkenes from methanol and/or

Acetic acid, ethanol, acetic aldehyde and possibly the secondary products thereof are prepared by the catalytic reaction of carbon monoxide and hydrogen. The catalyst contains applied onto a carrier, metallic rhodium, halide ions and magnesium salts or complex compounds of magnesium or compounds of magnesium with oxides of elements from groups III to VI of the Periodic Table.

A process for the preparation of dimethyl glycol by the hydrogenolysis of methylglycol formal in the presence of catalysts which consist of oxide mixtures of silicon and aluminum and/or of rare earths, as well as of metallic nickel and/or cobalt and/or copper, wherein the catalysts contain additionally as promoter metallic palladium and/or rhodium and/or platinum.

Process for the preparation of ethylene glycol-dimethylether (dimethyl

Acetic acid ethyl ester is prepared by passing ethylene over a fixed-bed catalyst composed of silicon dioxide, which has a surface from 50 to 200 m.sup.2 /g and which is impregnated with H.sub.2 SO.sub.4, diethylsulfate or ethylsulfuric acid or mixtures of these compounds, with periodically alternating quantities of acetic acid, at a temperature from 130.degree. to 170.degree. C, the acid concentration, calculated on ethylene, varying constantly over a range from 0.01 to 40% by mole.

Process for the manufacture of acetic acid ethyl ester

Glycolic acid or the esters thereof are prepared by reacting paraformaldehyde or trioxane or a mixture thereof with formic acid or a formic acid ester in the liquid phase at a temperature of from 70.degree. to 200.degree. C in the presence of a strongly acidic catalyst.

Process for the manufacture of glycolic acid or its esters

A process for the removal of formic acid from a crude mixture thereof with carboxylic acids by reacting the formic acid component of the mixture with a carboxylic anhydride and/or a compound forming an anhydride with a carboxylic acid, which comprises carrying out the reaction in the presence of an acidic catalyst.

Process for the purification of carboxylic acids

A process for the preparation of bromine and hydrogen bromide, which comprises reacting ammonium bromide with an oxygen containing gas at temperatures of from 200.degree. to 800.degree. C in the presence of oxidation catalysts is disclosed. Catalysts based on platinum group metals favor formation of HBr. Most other metal catalysts cause chiefly formation of bromine.

Growing community of inventors

Frankfurt am Main, Germany

Hans-Jurgen Arpe