Efficient one-pot synthesis of 2H-indazolo[2,1- b]phthalazinetrione derivatives with amino- functionalized nanoporous silica (SBA-Pr-NH 2 ) as catalyst Ghodsi Mohammadi Ziarani • Nina Hosseini Mohtasham • Negar Lashgari • Alireza Badiei Received: 12 August 2014 / Accepted: 5 October 2014 Ó Springer Science+Business Media Dordrecht 2014 Abstract Amino-functionalized SBA-15 (SBA-Pr-NH 2 ) with a pore size of 6 nm has been used as an efficient and reusable heterogeneous solid-base catalyst for preparation of 2H-indazolo[2,1-b]phthalazinetrione derivatives. The procedure involves three-component condensation of aromatic aldehydes, dimedone, and phthalhydrazide under solvent-free conditions. The catalyst can be easily removed from the reaction mixture and reused several times without substantial loss of reactivity. Keywords Amino-functionalized SBA-15 Á Indazolo[2,1-b]phthalazinetriones Á Phthalhydrazide Á Multicomponent reaction Á Solvent-free Introduction In recent years phthalazine derivatives have attracted much attention because of their pharmacological properties, for example antifungal [1], anticonvulsant [2], vasorelaxant [3], and anti-cancer [4] activity. Although several multicomponent methods have been reported for synthesis of phthalazine derivatives [5–8], development of new synthetic methods for efficient preparation of such heterocyclic structures is still an interesting challenge. Synthesis of 2H-indazolo[2,1-b]phthal- azine-1,6,11(13H)-trione derivatives by three-component reaction of phthalhydraz- ide, dimedone, and aldehydes, with silica sulfuric acid [9], H 2 SO 4 [10], Mg(HSO 4 ) 2 [11], heteropolyacids [12], molecular iodine [13], and dodecylphosphonic acid [14] G. Mohammadi Ziarani (&) Á N. Hosseini Mohtasham Department of Chemistry, Alzahra University, Vanak Square, Tehran, Iran e-mail: gmziarani@hotmail.com N. Lashgari Á A. Badiei School of Chemistry, College of Science, University of Tehran, Tehran, Iran 123 Res Chem Intermed DOI 10.1007/s11164-014-1845-9