反应详情

A stirred mixture of the disodium salt of 4-cyano-5-dicyanomethylidene-3-hydroxy-2-oxo-2,5-dihydropyrrole (23 parts). and dry N,N-dimethylformamide (180 parts) was cooled to -5° C. to -10° C. and N-n-butyl-N-(1-methylhexyl)aniline containing acetic anhydride (27%, 37 parts) was added followed by the dropwise addition of phosphorus oxychloride (26 parts) whilst maintaining the temperature at less than -5° C. The mixture was allowed to warm to room temperature and stirred for 20 hours. The reaction mixture was poured into a stirred mixture of ice and water (400 parts) and acetone (400 parts) was added before filtering off a solid. The solid was washed repeatedly with warm water (40° C.) and then dried at 50° C. to yield 3-(4-(N-butyl-N-(1-methylhexyl)amino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole (26.8 parts, 65%). A small sample this material was slurried in boiling methanol, collected by filtration, washed with methanol and dried at 50° C. to give 3-(4-(N-n-butyl-N-(1-methylhexyl)amino)phenyl)-4-cyano-5-dicyanomethylidene-2-oxo-2,5-dihydropyrrole m.p. 188° C.; λmax (CH2Cl2) 662 nm (εmax 60231); M/Z (EI) 415 (M+, 20%), 400 (15), 372 (12), 344 (100), 288 (33) and 272 (25).

1. additionwas added
2. temperaturewhilst maintaining the temperature at less than -5° C
3. additionwas added
4. filtrationbefore filtering off a solid
5. washThe solid was washed repeatedly with warm water (40° C.)
6. customdried at 50° C.