Patent ID: 7732631

Claim:
An eco-friendly improved process for the preparation of 2-chlorobenzylidenemalononitrile (CS), comprising the steps of: (a) preparing malononitrile suspension by adding 5-20% (wt %) malononitrile to water while constantly stirring and then adding 0.05-0.5% (v/v) of a catalyst selected from the group consisting of piperidine, pyridine, 2-picoline, 3-picoline, 4-picoline and morpholine with constant stirring at 20-30° C.; (b) condensing the malononitrile suspension prepared in step (a) with 2-chlorobenzaldehyde by adding 10-15% (w/v) of 2-chlorobenzaldehyde, cover for a period at 30-45 minutes so that the temperature of the reaction mixture remains below 50° C., constantly stirring for 20-40 minutes, then filtering the CS and drying it at 20-30° C. under water vacuum for 3-5 hours.