Hydrazonoyl halides: Useful building blocks for the synthesis of arylazoheterocycles

Site-selectivity in hydrazinolysis of 3,4'-bis-(functionalized carbonyl)-4,3'-bis(pyrazolyl)ketones. A convenient synthesis of 4-(pyrazol-3-yl)-2H-pyrazolo[3,4-d]-pyridazines

“…Also, in conjunction with our continued studies on the chemistry of hydrazonoyl halides, [3][4][5][6][7][8][9][10][11][12][13] we reported the synthesis of several 3,4'-bis(functionalized-carbonyl)-4,3'-bis(pyrazolyl) ketones of type 3 (Figure 1). 14,15 We have now studied the site-selectivity of the condensation between hydrazine hydrate and functionalized tricarbonyl compounds 3 which theoretically can lead to 4-(pyrazol-3-yl)-2H-pyrazolo[3,4-d]pyridazines 4 and/or 7-(pyrazol-4-yl)-2H-pyrazolo[3,4-d]pyridazines 5 ( Figure 1).…”

Regioselective synthesis of some functionalized 3,4’-bis-(pyrazolyl)ketones and chemoselectivity in their reaction with hydrazine hydrate

“…Their chemistry has attracted the interest of many research groups all over the world. At present, there are several review articles by Shawali et al covering their reactions and applications [1][2][3][4][5][6][7][8][9]. Also, literature reports indicate that many pyrazole derivatives found use in various pharmaceutical, agrochemical and many other applications [10][11][12][13][14][15][16][17].…”

Synthesis, reactions and antitumor activity of new β-aminovinyl 3-pyrazolyl ketones

“…Their reactions have been extensively studied and reviewed by one of the authors. [1][2][3][4][5][6][7][8][9][10] Furthermore, it is well known that the β-enaminones of the general formula R 2 N-CH=CH-COR' combine the ambident nucleophilicity of enamines with the ambident electrophilicity of enones. 11,12 Because of this, they have been utilized as versatile valuable precursors for heterocyclic synthesis.…”