Study Reaction of Pyrazolidine-3, 5-dione With Various Aldehyde

Pyrazolydine-3,5-dions are the base structures of phenyl butazones.Therefore pyrazolydine-3,5-dione is known as a very important substance in medicinal chemistry[1]. On the other hand cyanogen halides (and especially cyanogen bromide) are used for the cyanating reaction. There are a few evidences for bromination reaction too[2]. In this paper a new reaction of pyrazolydine-3,5-dion with cyanogen bromide in the presence of an organic base has been described affording spirofuro bispyrazolydine compound. Reaction of 1-phenylpyrazolidine-3,5-dione with cyanogen bromide and aromatic aldehydes in the presence of N-methyl morpholin leads to the efficient formation of a novel classes of stable heterocyclic 4-(4-nitrophenyl)-1,1'-diphenyl-1,2-dihydrospiro[furo[2,3-c]pyrazolidin]-3,3',5'(4H)-trione and 4,4'-((3-nitrophenyl)methylene)bis(1-phenylphyrazolidine-3,5-dione) and (E)-4(3,4-dimethoxybenzylidene)-1-phenylpyrazolidine-3,5-dione at 0°C and 1-(4-nitrophenyl)-5,5'-diphenyl-5,6,5',6'-tetrazaspiro[2.4.4]andecane-4,7,4',7'-tetraone at 70°C. Structure elucidation was carried out by 1H NMR, FT-IR spectroscopy. A proposed mechanism was discussed for the formation of products. The reaction of 4-nitro Benzaldehyde with BrCN and 3,5-pyrazolidine was afforded 4-(4-nitrophenyl)-1,1'-diphenyl-1,2-dihydrospiro[furo[2,3-c]pyrazolidin]-3,3',5'(4H)-trione, while 3-nitro Benzaldehyde were afforded 4,4'-((3-nitrophenyl)methylene)bis(1-phenylphyrazolidine-3,5-dione), respectively.