Basf Aktiengesellschaft

Heinz Hannebaum

Dieter Degner

Hermann P&uuml;tter

Hardo Siegel

Dieter Baumann

Manfred Stroezel

Walter Gramlich

Michael Steiniger

Heinz Nohe

Andreas Weiper-Idelmann

Hartwig Voss

Dieter Hermeling

Harald Laas

Fritz Beck

Peter Tavs

Hans Roos

Diethard Francke

Method for purifying phthalides

Method for producing phthalides

Selective hydrolysis of acetals or ketals in the presence of phthalides

Electrolytic plate stack cell

Preparation of phthalides

Benzaldehyde dialkyl acetals of the general formula I ##STR1## where R.sup.1 is C.sub.1 -C.sub.6 -alkyl, R.sup.2 is C.sub.1 -C.sub.6 -alkyl, C.sub.1 -C.sub.6 -alkoxy, halogen, cyano or carboxyalkyl where the alkyl group is of 1 to 6 carbon atoms, n is an integer of from 1 to 3 and the radicals R.sup.2 may be identical or different when n is &gt;1, are prepared by electrochemical oxidation of a substituted toluene compound of the general formula II ##STR2## by a process in which a substituted toluene compound II is oxidized in the presence of an alkanol R.sup.1 --OH and of an auxiliary electrolyte in an electrolysis cell, the reaction solution thus obtained is let down outside the electrolysis cell to a pressure which is from 10 mbar to 10 bar lower than the pressure in the electrolysis cell and

Preparation of benzaldehyde dialkyl acetals

Hydroxycarboxylic esters of the general formula ##STR1## where n is an integer from 0 to 10, R.sup.1 and R.sup.2 are each hydrogen, hydroxyl, alkoxy or an aliphatic or olefinic, straight-chain, branched or cyclic hydrocarbon radical, and R.sup.1 and R.sup.2 together may furthermore form an alkylene radical, and the hydrocarbon radicals may furthermore be substituted by halogen, hydroxyl, epoxy or nitrile, and R.sup.3 is a low molecular weight alkyl radical, are prepared by electrochemical oxidation of a hydroxyaldehyde of the general formula ##STR2## in the presence of an alcohol of the formula R.sup.3 OH and of an ionic bromide or chloride in an undivided electrolysis cell.

Preparation of hydroxycarboxylic esters

Benzaldehyde derivatives of the general formula I, where X is an oxygen atom or two R.sup.2 O groups and R.sup.1 and R.sup.2 are alkyl radicals of 1-4 carbon atoms, their preparation, and their use as odorants or odorant intermediates. ##STR1##

Novel benzaldehyde derivatives, their preparation, and their use

Biscarbamates, including novel one, of the general formula ##STR1## where R is alkyl of 1 to 8 carbon atoms and X is a hydrocarbon radical of 2 to 60 carbon atoms in which one or more carbon atoms may be replaced by hetero atoms and which may contain halogen atoms or ester, carbonyl or nitrile groups are prepared by electrochemically oxidizing formamides of the general formula ##STR2## in the presence of an alkanol of the formula ROH and of an ionic halide.

Preparation of biscarbamates and novel biscarbamates

Preparation of carbamic acid esters

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.

Process for the preparation of a

Benzaldehyde dialkyl acetals of the formula ##STR1## wherein R.sup.1 and R.sup.2 are each alkyl, are prepared by electrochemical oxidation of an alkyltoluene of the formula ##STR2## by a process in which the electrolyte used contains from 60 to 90% by weight of an alkanol of the formula R.sup.2 OH, from 8.5 to 40% by weight of the alkyltoluene and from 0.01 to 1.5% by weight of an HO.sub.3 S-containing acid.

2,5-Dialkoxy-2,5-dihydrofurans are prepared by a process in which 2,5-dihydrofuran is oxidized electrochemically in the presence of an alkanol.

Electrochemical preparation of 2,5-dialkoxy-2,5-dihydrofurans

A process for the preparation of alkyl-substituted benzaldehydes by electrooxidation of alkylbenzenes using graphite anodes coated with metal oxides or with carbides.

Preparation of alkyl-substituted benzaldehydes

A process for the preparation of 4-tert.-butylbenzaldehyde by electrochemical oxidation of 4-tert.-butyltoluene in the presence of an inorganic acid and of an alkylsulfonic, alkenylsulfonic or arylsulfonic acid.

Growing community of inventors

Ludwigshafen, Germany

Heinz Hannebaum