Coupling of bis-enaminones with benzenediazonium chloride and 3-diazo-1,2,4-triazole proved to be convenient routes for the synthesis of novel 3,4-bis(pyrazol-3-yl)pyrazoles and 3,6-bis(heteroaryl)pyrazolo[3,4-d]pyridazines which have not been reported previously. The structures of the products were elucidated on the basis of their spectral properties, elemental analyses and, wherever possible, by alternate synthesis.

Bis-enaminones (I) as Precursors for Synthesis of Novel 3,4-Bis(heteroaryl)pyrazoles and 3,6-Bis-(heteroaryl)-pyrazolo[3,4-d]pyridazines. -(SHAWALI*, A. S.; HABOUB, A. J. M.; J. Chem. Res. 35 (2011) 6, 341-345, http://dx.doi.org/10.3184/174751911x13079876877588 ; Dep. Chem., Fac. Sci., Cairo Univ., Cairo, Egypt; Eng.) -H. Toeppel

Reaction of hydrazine hydrate with 3,4-bis-(functionalized carbonyl)-4,3-bis(pyrazolyl)ketones proceeds regioselectively affording the corresponding 4-(pyrazol-3-yl)-2H-pyrazolo [3,4-d]pyridazine derivatives in high yields. The structures of the products were determined by spectroscopic and elemental analyses and supported by comparison with the possible isomers prepared by an independent route.

New bis-enaminones [(III) and (IX)] are synthesized starting from pyrazoles (I). Their synthetic utilities are successfully demonstrated on the regioselective preparation of novel polyaza-terheterocycles [(V), (VI), (VII), or (X), resp.]. Reaction mechanisms and selectivities are discussed. -(SHAWALI*, A. S.; HABOUB, A. J. M.; J. Heterocycl. Chem. 50 (2013) 1, 17-22, http://dx.

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