| abstract |
The present invention relates to a process for the preparation of a complexing agent, said process comprising the steps of: (a) providing a nitrile of general formula (I a) or (I b) (formula I a or I b), wherein M is selected from a base Metal and hydrogen and combinations thereof, (b) saponification with a total base amount of 2.5-2.9 moles of alkali metal hydroxide per mole of nitrile of general formula (I a) or (I b), respectively, and in step (b) ending with a pH of 9.5-11.5, (c) adding an amount of alkali metal hydroxide such that the total alkali content is 2.9 per mole of nitrile of general formula (I a) or (I b), respectively -3.15 moles, and (d) allow for further transformation. |