Abstract: The yield of 2,5,6-trimethyl-cyclohex-2-en-1-one is increased by reacting diethyl ketyone, in the presence of an alkali, with crotonaldehyde or a compound which is converted to crotonaldehyde under the reaction conditions chose, and working up the reaction mixture by distillation, by a method in which the distillation residue obtained is either(a) heated at from 120.degree. to 250.degree. C. in particular from 120.degree. to 200.degree. C., with the addition of a catalytic amount of an alkali, or(b) heated at from 150.degree. to 250.degree. C. without the addition of such a substance,and the mixture of 2,5,6-trimethylcyclohex-2-en-1-one and diethyl ketone which is formed from the distillation residue as a result of the heat treatment is separated by distillation.

Abstract: 2,3,6-Trimethylhydroquinone is prepared by catalytic hydrogenation of 2,3,6-trimethylquinone with hydrogen in the presence of a solvent by a continuous process in which the reaction is carried out over a platinum/alumina catalyst.

Abstract: Improved process for the preparation of salcomine useful as an oxidation catalyst for the oxidation of alkylated phenols to the corresponding alkylated p-benzoquinones by reacting salicylaldehyde with ethylenediamine in a mole ratio of about 2:1 and a cobalt salt in a liquid reaction medium wherein the reaction medium is a linear or cyclic carboxamide which is disubstituted on the nitrogen, in particular dimethylformamide, and the cobalt salt is cobalt carbonate or with the cobalt hyroxide carbonate, 2 CoCO.sub.3.3 Co(OH).sub.2.H.sub.2 O. Preparation of the salcomine in accordance with the invention offers significant advantages, both in the preparation of the salcomine itself and in the subsequent oxidation of the trimethylphenol to trimethyl-p-benzoquinone utilizing the salcomine.

Abstract: Substituted phenols of the general formula I ##STR1## where R.sup.1, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are each hydrogen or an aliphatic or aromatic hydrocarbon radical, are prepared by dehydrogenating a cyclic alcohol of the general formula II ##STR2## or a cyclic ketone of the general formula III ##STR3## where one of the broken lines can be an additional C-C bond, in the gas phase at from 150.degree. to 380.degree. C. over a supported noble metal catalyst, by a process in which the dehydrogenation catalyst used is palladium or platinum on an aluminum spinel carrier, in particular an aluminum spinel which has a BET specific surface area of from 5 to 150 m.sup.2 /g or, for the dehydrogenation of cyclohexenones, preferably from 10 to 50 m.sup.2 /g. Particularly suitable aluminum spinels are those which, in addition to aluminum, contain magnesium, zinc, cobalt or nickel.

Abstract: Production of aldehydes and alcohols by hydroformylation of olefinically unsaturated compounds with carbon monoxide and hydrogen at elevated temperature and superatmospheric pressure in the presence of carbonyl complexes of metals of group 8 of the Periodic System which have been modified with trisubstituted phosphines in which two substituents are lower alkyl radicals and the third substituent is a higher aliphatic radical. Aldehydes and alcohols are known to be solvents; they are used on a large scale for the production of plasticizers for polyvinyl chloride.

Abstract: An improved process for the production of aldehydes and alcohols by the oxo process comprising the reaction of olefinically unsaturated compounds with carbon monoxide and hydrogen at elevated temperatures and elevated pressures in the presence of carbonyl complexes of metals in Group VIII of the Periodic Table modified by trisubstituted organic phosphines and in the presence of alkali or alkaline earth metal salts of carboxylic acids, the improvement comprising the use of modifying agents which consist of trisubstituted organic phosphines containing one or more carboxylic acid groups, at least one of which is present in the form of its alkali metal or alkaline earth metal salt.