Patent ID: 8022242
Filing Date: 2011-09-20
Classification: C07C

Abstract:
1. A process for preparing alkali metal or alkaline earth metal tricyanomethanides having a purity of at least 99% by weight and a halide content of not more than 20 ppm, wherein, in a first step, malononitrile is converted into the corresponding alkali metal or alkaline earth metal tricyanomethanide in the presence of water and an acid by parallel addition of a halocyan or dicyan and also an alkali metal or alkaline earth metal base and a pH of from 4.0 to 9.5, is maintained at least during the addition of the halocyan and the alkali metal or alkaline earth metal tricyanomethanide initially formed is recrystallized from a different solvent in a second step, characterized in that the alkali metal or alkaline earth metal base contains at least one alkali metal or alkaline earth metal selected from the group consisting of lithium, sodium, potassium, calcium, magnesium and barium.