Heteropoly Acid in Ionic Liquid - An Efficient Catalyst for the Preparation of 2H-Indazolo[2,1-b]Phthalazine-Triones

Abstract

2H-Indazolo[2,1-b]phthalazine-1,6,11(13H)-trione derivatives were synthesized in a simple and efficient method from the three-component condensation reaction of phthalhydrazide, dimedone, and aromatic aldehydes by H 3 PW 12 O 40 in ionic liquid in good to excellent yields and short reaction times. The ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim]BF 4 ) offered the best results in terms of yield of the products. It was observed that a homogeneous reaction medium proved beneficial for the yield of the reaction.

Ionic Liquid 4-(3-Methyl-1-imidazolio)-1-butanesulfonic Acid Hydrogen Sulfate-catalyzed Synthesis of Phthalazinetrione Derivatives

“…The procedure was also applicable to aliphatic aldehydes, which gave satisfactory yields although longer reaction times were required in comparison with aromatic aldehydes (Table 4, entries 10 and 11). In addition, the three-component reactions using dimedone (Table 4, entries 1-9) generally gave better yields than cyclohexane-1,3-dione (Table 4, entries [12][13][14][15][16][17][18][19].…”

“…In addition, these compounds show good promise as new luminescence materials and fluorescence probes [12]. There are several methods to synthesize phthalazine derivatives, including the reaction of phthalhydrazide, aldehydes and dimedone or cyclohexane-1,3-dione catalyzed by p-TSA [13], H 2 SO 4 [14], H 4 SiW 12 O 40 [15], H 3 PW 12 O 40 [16], silica sulfuric acid [17], silicasupported polyphosphoric acid [18], TMSCl [19], phosphomolybdic acid (PMA)-SiO 2 [20], N,N,N ,Ntetrabromobenzene-1,3-disulfonamide and poly(Nbromo-N-ethylbenzene-1,3-disulfonamide) [21]. Most recently a one-pot four-component reaction for the synthesis of phthalazine derivatives was reported using Ce(SO 4 ) 2 · 4H 2 O [22] as catalyst.…”

“…[BmIm]BF 4 has been used as solvent for the synthesis of phthalazine derivatives [14,16]. However, the dosages of [BmIm]BF 4 were very large.…”

Magnetic Nanoparticle Immobilized N-Propylsulfamic Acid as a Recyclable and Efficient Nanocatalyst for the Synthesis of 2H-indazolo[2,1-b]phthalazine-triones in Solvent-Free Conditions: Comparison with Sulfamic Acid

“…16 Although several reports on the synthesis of phthalazines fused with indazole have been published. [17][18][19][20][21][22][23][24][25][26] However, the development of an efficient and versatile method for the preparation of fused phthalazine with indazole is an active ongoing research area, and there is a potential for further improvement toward green chemistry.…”

Efficient CAN catalyzed synthesis of 1H-indazolo[1,2-b] phthalazine-1,6,11-triones: An eco-friendly protocol

“…These compounds have also proved to be promising luminescence materials and fluorescence probes [35]. Several methods have been reported for the synthesis of phthalazine derivatives [36][37][38][39][40][41]. Unfortunately, many of these methods are plagued with a number of limitations, such as harsh reaction conditions, unsatisfactory yields, tedious work-up procedures, relatively long reaction times, poor solvent scope and the use of stoichiometric and relatively expensive reagents.…”