Phosphorus oxychloride → 3-(4-(N-(2-ethylhexyl)-N-propylamino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole

Participants

Reaction Conditions

Reaction Steps

A stirred mixture of disodium salt of 4-cyano-5-dicyanomethylidene-3-hydroxy-2-oxo-2,5-dihydropyrrole (29.9 parts) and dry N,N-dimethylformamide (150 parts) was cooled to -10° C. and N-(2-ethylhexyl)-N-propylaniline containing 30% acetic anhydride (63 parts) was added followed by the dropwise addition of phosphorous oxychloride (34 parts) maintaining the temperature at less than -5° C. The mixture was allowed to warm up to room temperature and stirred for 20 hours. The reaction mixture was poured into a stirred mixture of ice and water (200 parts) and acetone (200 parts) and then stirred for 0.5 hours. The solid was filtered off, washed with hot water and dried under vacuum to give 3-(4-(N-(2-ethylhexyl)-N-propylamino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole (48.5 parts, 90%).

Provenance & Evidence