137156-91-3Relevant academic research and scientific papers
A novel one-pot synthesis of substituted-1H-pyridazin-4-ones and their conversion to substituted-2H-pyrazolopyridazines
Patel, Himatkumar V,Pandey, Sudhanshu P,Fernandes, P S,Vyas, Kavita A
, p. 932 - 935 (2007/10/02)
Pentane-2,3,4-trione 3-arylhydrazones (1), when treated with AcCl/Ac2O in the presence of conc.H2SO4/p-TsOH, give N-acetylpentane-2,3,4-trione 3-arylhydrazones (2) and 3-acetyl-1-aryl-6-methyl-1H-pyridazin-4-ones (4).Compound 1e on treatment with AcCl/Ac2O in the presence of Et3N/(i-Pr)2NEt furnishes the pyridazin-4-one (4e).Treatment of 1 with NaH in THF followed by addition of AcCl at 0-10 deg C affords the N-acetyl derivatives (2).Similar treatment of 2 provides the rearranged product heptane-2,3,4,6-tetraone-3-arylhydrazones (3) which on heating give 4.The same compounds (4) are also directly synthesised by reacting 1 with AcCl/Ac2O in the presence of conc.H2SO4 or preferably p-TsOH on prolonged reflux.These pyridazinones (4) on treatment with N2H4 get transformed to 2-aryl-3,7-dimethyl-2H-pyrazolopyridazines (5).
