Dsm Chemie Linz Gmbh

Dsm Fine Chemicals Austria Gmbh

Gunter Eichberger

Harald Poschko

Wolfgang Huber

Gerhard Burschik

Process for the preparation of 2-acetylcarboxylic esters by reacting an acetoacetic ester having 1 to 6 C atoms in the alkyl moiety with an aliphatic aldehyde having 1 to 12 C atoms at 0 to 40.degree. C. in the presence of a condensation catalyst, subsequently removing the water of reaction formed and unreacted starting materials and then hydrogenating the material at 20-160.degree. C., the temperature in the first hydrogenation phase being between 20 and 90.degree. C. and the temperature in the second phase being increased to 50 to 160.degree. C., depending on the starting temperature.

Process for the preparation of 2-acetylcarboxylic esters

Process for the purification of 5H-dibenz�b,f!a-zepine, which comprises evaporating 5H-dibenz�b, f!azepine under reduced pressure from a reaction mixture obtained by catalytic dehydrogenation of 10,11-dihydro-5H-dibenz-�b,f!azepine in the 1st step and depositing it as a solid, suspending the deposited product in an aromatic hydrocarbon in the 2nd step and then isolating pure 5H-dibenz�b,f!azepine.

Growing community of inventors

Weisskirchen, Austria

Gunter Eichberger