Reactions of Cyclic Oxalyl Compounds, Reaction of Some Furan-2,3-diones with Various Hydrazine Derivatives

Abstract

Furan-2,3-diones (1a-c) react with various hydrazines (2a-d) in boiling benzene to yield the pyrazole-3-carboxylic acids (3a-c) and the 1,2-dihydropyridazine-3,4-diones (6a-d). The structures of all products were confirmed by elemental analysis, IR, ¹H- and ¹³C-  NMR spectroscopic measurements. Thermal decomposition of 4-benzoyl-1-(2,4-dinitrophenyl)-5-phenyl- 1H-pyrazole-3-carboxyl ic acid (3b) leads to the formation of [1-(2,4-dinitrophenyl)-5-phenyl- 1H-pyrazol-4-yl] phenylmetbanone (5). The pyrazole-3-carboxylic acid chloride (4) was obtained from the reaction of 3a and thionyl chloride.