| abstract |
The invention concerns a method of producing compounds containing NH2 groups by the hydrogenation of compounds which include at least one carbon-nitrogen bond with hydrogen in the presence of a catalyst, at a temperature not below room temperature and at an elevated hydrogen partial pressure, optionally in the presence of a solvent. The hydrogenation is carried out under the following conditions: a) a catalyst containing cobalt and/or iron is used, b) if the yield, based on the compound being hydrogenated, and/or the selectivity, based on the desired product, drops below a defined value or if the amount of an undesired side-product increases to more than a defined value, the hydrogenation is interrupted by stopping the feed of the compound being hydrogenated and, if present, also the solvent, c) the catalyst is treated with hydrogen at a temperature in the range 150 to 400 DEG C, using a hydrogen pressure of 0.1 to 30 MPa and a treatment time of 2 to 48 h and d) the hydrogenation is subsequently continued, and the catalysts containing cobalt and/or iron are regenerated. |