Benzodiazepinone scaffold is found in many of the pharamaceutical products (Fig. 1) like the drugs used for anti-psychotic, anxiety disorders, classical CNS treatments such as sedatives, epilepsy, muscle relaxants, anxiolytic, anti-convulsant agents like clozapine, bromazepam, prazepam, clonazepam, clobazam, arfendazem, lofendazem and CP-1414S.1–3 2,3-dihydro-1H-1,5-benzodiazepin-2-one derivatives can be used as potential imaging agents for the metabotropic glutamate-2- receptors.4 The benzodiazepinone in diazepam5 is extensively used for the synthesis of variety of sedatives prescribed to induce sleep for the people who are suffering insomnia disease and also it is a “privileged scaffold” for the prodease inhibitors 7-Tm receptors.6
Though a number of synthetic methods have been attempted for the synthesis of 1,5-benzodiazepine via the coupling of amines and acids,7 condensation of amine with aldehydes, ketones, alkynes using different catalysts such as HY,8 photocatalyst9 and also by the use of metals such as Ce(III),10 Au,11 carbon supported Zirconia,12 Heteropolyacid,13 Cu(II) clay,14 Fe-oxide nanomaterial,15 Graphene supported TiO2,16 Ionic liquid,17 biodegradable itaconic acid,18, there are only very few reports are available for the synthesis of bezodiazepinone derivatives. Mostly, the benzodiazepinone derivatives are synthesized from the reaction of 1,2-diaminobenzene with g-pyrone,19 condensation of amine with α,β- unsaturated carboxylic acid,20 α-cyanocinnamates,21 4-hydroxy coumarin, glycidic ester22 using the catalysts like Cu(I) nanoparticles,23 K2CO3 / TBAB,24 Phase transfer catalyst and Trimethylamine/THF.25 However, most of the reported procedures finds many notable drawbacks such as difficulties in the preparation of catalyst and its extraction back from the reaction medium, longer reaction times, a limited scope of substrates, tedious work-up, the use of hazardous organic solvents and especially the lack of selectivity etc.,
The recent research on the applications of hierarchically architechtured nanoporous material has been receiving great attention over the past one decade due to its versatile structural characteristics such as high surface area, hybrid porosity with large pore volumes that can alleviate diffusional limitations over conventional zeolites with solely microporous skeleton.26 It also finds potential applications in the development of multidisciplinary study such as hydrocarbon isomerisation, cracking, fine chemical synthesis, catalysis, drug delivery etc., 27 Recently We have proved the efficacy of its catalytic action in the chemoselective synthesis of 1,2-disubstituted benzimidazoles,28 regioselective o-allylation29 and in Tsuji-Trost reaction.30