Solvent-free multicomponent assembling of isatins, malononitrile, and dimedone: fast and efficient way to functionalized spirooxindole system

6′-Amino-5,7-dibromo-2-oxo-3′-(trifluoromethyl)-1′H-spiro[indoline-3,4′-pyrano[2,3-c]pyrazole]-5′-carbonitrile

“…Signals from four carbon atoms in the 13 C spectrum (carbons of the pyrazole fragment) are not observed due to too large line broadening caused by the tautomerism of the pyrazole N-H proton (Scheme 2). Taking into consideration our previous results [16,17] and literature data [19], the following mechanism for the multicomponent transformation of 5,7-dibromoisatin 1, malononitrile 2, and 5-(trifluoromethyl)-2,4-dihydro-3H-pyrazol-3-one 3 was proposed, as shown in Scheme 3.…”

“…We previously carried out a multicomponent transformation of isatins, malononitrile, and different C-H acids into functionalized spirooxindoles [15][16][17][18]. These reactions were carried out both in solution and in 'on-solvent' and 'solvent-free' formats.…”

Engaging Isatins in Multicomponent Reactions (MCRs) – Easy Access to Structural Diversity

“…Using isatin derivatives, malononitrile, and dimedone, the reaction proceeded smoothly by grinding the starting materials and the NaOAc catalyst in a mortar at room temperature. Despite the poor substrate scope that was observed, the reactions had short reaction times and afforded the target products in moderate to excellent yields (Scheme 37A) [66] . Chouha et al .…”

“…NEt 3 [56] DBU [58] Na 2 CO 3 [61] DMAP [62] DABCO [81] , [82] , [85] , [157] C 4 (DABCO) 2 .2OH [83] NaOAc [94] , [66] , [110] urea [95] TEA [111] CsF [113] …”

Recent applications of isatin in the synthesis of organic compounds

“…115 This reaction has been widely studied and different catalysts such as [Amb]L-prolinate, 116 tetrabutylammonium bromide (TBAB), 117 boron nitride supported iron oxide (BN@Fe3O4), 118 AI-ITQ-HB, 119 [bmim]OH, 120 Fe3O4, 121 carbon nanotube (CNT), 122 NaOAc, 123 CuFe2O4 nanoparticles 124 and trisodium citrate dihydrate 125 were used in this reaction.…”