Ciba-geigy Corporation

Rolf Bader

Dieter Reinehr

Paul Radimerski

Peter Waldvogel

Leopold Kung

Peter Flatt

A process for the preparation of 2-alkyl-6-methyl-N(1'-methoxy-2'-propyl)-aniline by catalytic reductive alkylation wherein at least one mole equivalent of methoxyacetone is reacted with one mole equivalent of 2-alkyl-6-methyl-aniline in a liquid medium without an additional solvent, in the presence of a platinized carbon catalyst and hydrogen and in the presence of an acid cocatalyst under a hydrogen pressure of between 2.times.10.sup.5 and 1.times.10.sup.6 Pa at a temperature between 20.degree. and 80.degree. C., characterized in that the reaction mixture contains water from the beginning of the reaction and after the hydrogenation, base is added, the reaction mixture is filtered to separate the catalyst and the title compound recovered from the filtrate. The process is particularly useful for the preparation of N-substituted chloracetanilide herbicides.

Process for the preparation of

A new improved process for producing pyridinaldehydes and hydrazone derivatives thereof, for example, pyridinaldehyde-phenylhydrazones, is described. This comprises reacting an aminomethylpyridine with an aldehyde or a ketone to give a compound of the formula ##STR1## isomerizing the compound (III), in the presence of suitable catalysts, to a compound of the formula ##STR2## and converting the compound (V), in the presence of an acid and optionally in the presence of a hydrazine, into a pyridinaldehyde or a pyridinaldehyde-hydrazone. It is possible to produce by the process according to the invention pyridinaldehydes and pyridinaldehyde-hydrazones in a simple manner, under mild ecologically favorable conditions and in good to very good yields.

Process for producing pyridinaldehydes

An improved process for producing pyridinaldehydes and hydrazone derivatives thereof, for example, pyridinaldehyde-phenylhydrazones, is described. This comprises reacting a aminomethylpyridine with an aldehyde or a ketone to give a compound of the formula ##STR1## isomerizing the compound (III), in the presence of suitable catalysts, to a compound of the formula ##STR2## and converting the compound (V), in the presence of an acid and optionally in the presence of a hydrazine, into a pyridinaldehyde or a pyridinaldehyde-hydrazone. It is possible to produce by the process according to the invention pyridinaldehydes and pyridinaldehyde-hydrazones in a simple manner, under mild ecologically favorable conditions and in good to very good yields.

Process for producing hydrazone derivatives of pyridinaldehydes

A process for producing benzotriazoles of the formula I ##STR1## wherein R.sub.1 is hydrogen or chlorine,

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Riehen, Switzerland

Rolf Bader