170874-97-2Relevant academic research and scientific papers
PREPARATION AND REACTIONS OF SOME 2-THIENYL AND 3-THIENYL PYRIDAZINONES AND PYRIDAZINES
Powell, Paul,Sosabowski, Michael H.
, p. 1840 - 1852 (2007/10/03)
The preparation and reactions of some pyridazinone derivatives with 2- and 3-thienyl substituents are described.Precursor 4-oxobutanoic acids Ar2COCH2CH(Ar1)CO2H (Ar1=Pb, Ar2=2-thienyl and Ar1=2-thienyl, Ar2=Pb) were obtained by addition of HCN to the chalcones Ar1CH=CHCOAr2 followed by acid hydrolysis of the resulting nitrile.Nitriles, ArCOCH(CH3)CH2CN were prepared by the Michael-Stetter reaction and converted via the acids to the 4,5-dihydropyridazin-3(2H)-ones.Two methods wereused to obtain pyridazin-3(2H)-ones viz oxidation of the 4,5-dihydro derivatives with selenium dioxide and base-catalyzed condensation of methanal or aryl aldehydes at the 4-position of the 4,5-dihydro compound.
