Abstract: Process for recovering a pyridine-2,3-dicarboxylic acid from a process stream in the preparation process of the pyridine-2,3-dicarboxylic acid in which the process stream is subjected to nanofiltration at a pH higher than 4.5 and the pyridine-2,3-dicarboxylic acid-containing concentrate is utilised. Preferably, the pH is chosen to be between 7 and 9 and the concentration factor in nanofiltration greater than 3.In a suitable embodiment the process stream is formed by the mother liquor obtained in the preparation of pyridine-2,3-dicarboxylic acid by oxidising a suitable quinoline or the corresponding 2,3-lutidine and separating the solid material.

Abstract: The present process involves preparing dibenzylamine through the hydrogenation of benzaldehyde in the presence of ammonia and a catalyst containing palladium using a small amount of solvent or dispersion medium. With the present process, dibenzylamine can be prepared with high selectivity in a relatively short reaction time and with complete conversion of the benzaldehyde, at which makes it commercially attractive. In the present process, a palladium-carbon catalyst is preferably used.