Ciba-geigy Corporation

Siegfried Kintopf

Rudolf Maul

Ulrich Kress

Hans Stephan

Hans Wolf Jung

Heinz Issler

Lutz Konig

Wilfried Kloss

Reinhard Knapp

A process for the preparation of 4-hydroxy-2,2,6,6-tetramethyliperidine (HTMP) by hydrogenation of triacetonamine (TAA) in the presence of an Ni, Co, Ru, Rh, Os or Ir hydrogenation catalyst is described. The process is carried out in the melt without a solvent.

Process for the preparation of 4-hydroxy-2,2,6,6-tetramethylpiperidine

There is disclosed a process for the preparation of 1-(2-hydroxyethyl-2,2,6,6-tetramethyl-4-piperidinol from triacetoneamine, which comprises first reducing triacetoneamine in water and/or a polar organic solvent by catalytic hydrogenation to 2,2,6,6-tetramethyl-4-piperidinol, and adding a catalytic amount of acid to the resultant solution, without isolation of the intermediate, after optional concentration of the solution by distillation, and subsequently reacting the 2,2,6,6-tetramethyl-4-piperidinol with ethylene oxide. 1-(2-Hydroxyethyl)-2,2,6,6-tetramethyl-4-piperidinol is a useful light and heat stabilizer for plastics and is, in addition, a valuable intermediate for the synthesis of further light stabilizer additives.

Process for the preparation of

A process for the production of 2-aryl-2H-benzotriazoles comprises reducing and cyclizing the corresponding o-nitroazobenzenes with hydrogen at a temperature in the range of about 20.degree. C. to about 100.degree. C. and at a pressure in the range of about 15 psia (1 atmosphere) to about 1000 psia (66 atmospheres) in an organic solvent mixture containing an organic amine at a pH over 10 in the presence of noble metal hydrogenation catalyst, preferably palladium. High yields of pure product are obtained with a concomitant reduction of undesired by-products and a reduction in effluent pollution problems.

Process for the production of 2-aryl-2H-benzotriazoles

In the manufacture of monomethyl-tin trichloride by disproportionation of tin tetrachloride with dimethyl-tin dichloride, high yields are achieved by employing phosphines, arsines and stibines or onium compounds of elements of the fifth main group in the periodic system as the catalyst, optionally together with a co-catalyst.

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Bensheim/Bergstrasse, Germany

Siegfried Kintopf