94786-53-5Relevant articles and documents
Ring Opening and Substitution Reactions of 4,4-Dihalo-pyrazolin-5-ones with Nucleophiles
Kirschke, Klaus,Lutze, Gerhard,Schmitz, Ernst
, p. 367 - 373 (2007/10/02)
1-Aryl-4,4-dihalo-3-methyl-pyrazolin-5-ones (1a-c) undergo ring opening with alkoxides and form alkyl 3-arylazo-2-halo-2-butenoates (2a-d).Analogous reactions take place with ammonia and amines. 4-Nitro-phenoxide reacts with substitution of both halogens to the 4,4-bis(4-nitro-phenyl)-compound (5).Phenols are selectively ortho-brominated by the title compounds 1a and b.