Bayer Aktiengesellschaft

Frank Jelitto

Helmut Fiege

Albert Schnatterer

Claus Dreisbach

Edwin Ritzer

Robert Sollner

Karl-Heinz Theisen

Peter Skornia

The present invention relates to a process for preparing optionally substituted benzyl carbazates of formula (I) ##STR1## wherein each R.sup.1 independently represents C.sub.1 -C.sub.4 -alkyl, C.sub.1 -C.sub.4 -alkoxy, di(C.sub.1 -C.sub.4 -alkyl)amino, nitro, halogen, hydroxyl, the group X-R.sup.3, wherein X represents O or S and R.sup.3 represents straight-chain or branched C.sub.1 -C.sub.4 -alkyl, the group COOR.sup.4, wherein R.sup.4 represents C.sub.1 -C.sub.4 -alkyl, the group NR.sup.5 R.sup.6, wherein R.sup.5 and R.sup.6 independently represent C.sub.1 -C.sub.4 -alkyl, or a C.sub.3 -C.sub.6 -cycloalkyl group that is optionally substituted by straight-chain or branched C.sub.1 -C.sub.4 -alkyl groups, and

Process for preparing benzyl carbazates

A process for separating off poorly soluble by-products from reaction mixtures which are produced in the oxidation of p-cresol with oxygen or an oxygen-containing gas in methanol as solvent in the presence of alkali metal hydroxide and in the presence of metal compounds as catalyst, is characterized in that, after the oxidation, excess alkali is neutralized to the extent that a salt precipitate forms and this salt precipitate is separated off together with the poorly soluble by-products.

Process for the recovery of 4-hydroxybenzaldehyde from reaction mixtures

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Bergisch Gladbach, Germany

Frank Jelitto