Generic placeholder image

Current Organocatalysis

Editor-in-Chief

ISSN (Print): 2213-3372
ISSN (Online): 2213-3380

Research Article

Agro-Waste Sourced Catalyst as an Eco-Friendly and Sustainable Approach for Knoevenagel Condensation Reaction

Author(s): Krishnappa B. Badiger, Santosh Y. Khatavi, Prashant B. Hiremath and Kantharaju Kamanna*

Volume 9, Issue 2, 2022

Published on: 27 January, 2022

Page: [179 - 194] Pages: 16

DOI: 10.2174/2213337209666211222145453

Price: $65

Abstract

Background: The present work describes an eco-friendly and sustainable approach for the Knoevenagel condensation of an aromatic aldehyde with ethyl cyanoacetate, and salicylaldehyde with Meldrum acid for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin (2-oxo-2H-1-benzopyran) derivatives, respectively. The reaction was performed under green catalytic media-Water Extract of Watermelon Fruit Peel Ash (WEWFPA), which is an eco-friendly protocol derived from the agro-waste feedstock. Various protocols have been reported for the synthesis of Knoevenagel condensation reaction using a hazardous catalyst or/and solvents found toxic to the environment, requiring longer reaction time, giving poor yield, and requiring purification of the final product. The method at hand provides several added advantages like: being a completely green method, economic, inexpensive catalyst, and the final product isolated is in pure form with good yield.

Objective: The objective of the study was to develop a green methodology for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives.

Results: The agro-waste based catalyst developed in the present study avoids the use of external inorganic/ organic bases and additives. Knoevenagel condensation of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives is carried out under room temperature using microwave irradiation, which is a solvent-free synthesis, requiring less time and giving better yield.

Methods: We have demonstrated that WEWFPA can be employed as a green homogenous agrowaste for the synthesis of ethyl benzylidenecyanoacetate and 3-carboxy coumarin derivatives under rt stirring and microwave irradiation in a very economical way. The developed method is found to be simple and robust, non-hazardous and solvent-free to obtain the target product.

Conclusion: In conclusion, we have established an efficient, simple, agro-waste based catalytic approach for the synthesis of ethylbenzylidenecyanoacetate and 3-carboxy coumarin derivatives employing WEWFPA as an efficient catalyst under rt stirring and microwave synthesis. The method is a green, economical and eco-friendly approach for the synthesis of Knoevenagel condensation products. The advantages of the present approach are that the reaction is a solvent-free synthesis, requiring no external metal catalyst, chemical base free, short reaction time and excellent yield of product. The catalyst is agro-waste derived, which is abundant in nature, thus making the present approach a greener one.

Keywords: Knoevenagel condensation, ethyl benzylidenecyanoacetate, 3-carboxy coumarin, feedstock, eco-friendly, agrowaste.

Graphical Abstract

[1]
Kaur, N. Microwave-assisted synthesis: fused five-membered n-heterocycles. Synth. Commun., 2015, 45, 789-823.
[http://dx.doi.org/10.1080/00397911.2013.824984]
[2]
Alcázar, J.; Oehlrich, D. Recent applications of microwave irradiation to medicinal chemistry. Future Med. Chem., 2010, 2(2), 169-176.
[http://dx.doi.org/10.4155/fmc.09.144] [PMID: 21426184]
[3]
Katritzky, A.R.; Rees, C.W. Comprehensive heterocyclic chemistry; Pergamon Press: New York, 1984, pp. 1-8.
[4]
Balaban, A.T.; Oniciu, D.C.; Katritzky, A.R. Aromaticity as a cornerstone of heterocyclic chemistry. Chem. Rev., 2004, 104(5), 2777-2812.
[http://dx.doi.org/10.1021/cr0306790] [PMID: 15137807]
[5]
Brichacek, M.; Njardarson, J.T. Creative approaches towards the synthesis of 2,5-dihydro- furans, thiophenes, and pyrroles. One method does not fit all! Org. Biomol. Chem., 2009, 7(9), 1761-1770.
[http://dx.doi.org/10.1039/b900236g] [PMID: 19590767]
[6]
Sheldon, R.A. Catalysis: the key to waste minimization. J. Chem. Technol. Biotechnol., 1997, 68, 381-388.
[http://dx.doi.org/10.1002/(SICI)1097-4660(199704)68:4<381::AID-JCTB620>3.0.CO;2-3]
[7]
Dabholkar, V.V.; Ansari, F.Y. Novel pyrimidine derivatives by sonication and traditional thermal methods. Green Chem. Lett. Rev., 2010, 3, 245-248.
[http://dx.doi.org/10.1080/17518251003749353]
[8]
Eco-friendly synthesis of fine chemicals; Ballini, R., Ed.; Royal Soc. Chem: UK, 2009, pp. 275-292.
[http://dx.doi.org/10.1039/9781847559760]
[9]
Santagada, V.; Perissutti, E.; Caliendo, G. The application of microwave irradiation as new convenient synthetic procedure in drug discovery. Curr. Med. Chem., 2002, 9(13), 1251-1283.
[http://dx.doi.org/10.2174/0929867023369989] [PMID: 12052166]
[10]
Dinesh, S.; Shikha, G.; Bhavana, G.; Nidhi, S.; Dileep, S. Biological activities of purine analogues: a review. J. Pharma. Sci. Innov., 2012, 2, 29-34.
[11]
Radha, Y.; Manjula, A.; Reddy, B.M.; Rao, B.V. Synthesis and biological activity of novel benzimidazoles. Indian J. Chem., 2011, 50B, 1762-1773.
[12]
Tatsuta, M.; Kataoka, M.; Yasoshima, K.; Sakakibara, S.; Shogase, Y.; Shimazaki, M.; Yura, T.; Li, Y.; Yamamoto, N.; Gupta, J.; Urbahns, K. Benzimidazoles as non-peptide luteinizing hormone-releasing hormone (LHRH) antagonists. Part 3: Discovery of 1-(1H-benzimidazol-5-yl)-3-tert-butylurea derivatives. Bioorg. Med. Chem. Lett., 2005, 15(9), 2265-2269.
[http://dx.doi.org/10.1016/j.bmcl.2005.03.030] [PMID: 15837306]
[13]
Sabat, M.; VanRens, J.C.; Laufersweiler, M.J.; Brugel, T.A.; Maier, J.; Golebiowski, A.; De, B.; Easwaran, V.; Hsieh, L.C.; Walter, R.L.; Mekel, M.J.; Evdokimov, A.; Janusz, M.J. The development of 2-benzimidazole substituted pyrimidine based inhibitors of lymphocyte specific kinase (Lck). Bioorg. Med. Chem. Lett., 2006, 16(23), 5973-5977.
[http://dx.doi.org/10.1016/j.bmcl.2006.08.132] [PMID: 16997556]
[14]
Sun, L.; Chiu, D.; Kowal, D.; Simon, R.; Smeyne, M.; Zukin, R.S.; Olney, J.; Baudy, R.; Lin, S. Characterization of two novel N-methyl-D-aspartate antagonists: EAA-090 (2-[8,9-dioxo-2,6-diazabicyclo [5.2.0]non-1(7)-en2-yl]ethylphosphonic acid) and EAB-318 (R-α-amino-5-chloro-1-(phosphonomethyl)-1H-benzimidazole-2-propanoic acid hydrochloride). J. Pharmacol. Exp. Ther., 2004, 310(2), 563-570.
[http://dx.doi.org/10.1124/jpet.104.066092] [PMID: 15075380]
[15]
Borza, I.; Bozó, E.; Barta-Szalai, G.; Kiss, C.; Tárkányi, G.; Demeter, A.; Gáti, T.; Háda, V.; Kolok, S.; Gere, A.; Fodor, L.; Nagy, J.; Galgóczy, K.; Magdó, I.; Agai, B.; Fetter, J.; Bertha, F.; Keserü, G.M.; Horváth, C.; Farkas, S.; Greiner, I.; Domány, G. Selective NR1/2B N-methyl-D-aspartate receptor antagonists among indole-2-carboxamides and benzimidazole-2-carboxamides. J. Med. Chem., 2007, 50(5), 901-914.
[http://dx.doi.org/10.1021/jm060420k] [PMID: 17290978]
[16]
Smith, S.A.; Markwell, R.E. Benzimidazoles As 5-Lypoxygenase inhbtors. US Patent (4925853), 1990.
[17]
Stanley, B.G.; Magdalin, W.; Seirafi, A.; Nguyen, M.M.; Leibowitz, S.F. Evidence for neuropeptide Y mediation of eating produced by food deprivation and for a variant of the Y1 receptor mediating this peptide’s effect. Peptides, 1992, 13(3), 581-587.
[http://dx.doi.org/10.1016/0196-9781(92)90093-I] [PMID: 1326105]
[18]
Nutescu, E.A.; Shapiro, N.L.; Chevalier, A. New anticoagulant agents: direct thrombin inhibitors. Cardiol. Clin., 2008, 26(2), 169-187, v-vi.
[http://dx.doi.org/10.1016/j.ccl.2007.12.005] [PMID: 18406993]
[19]
Penning, T.D.; Zhu, G.D.; Gong, J.; Thomas, S.; Gandhi, V.B.; Liu, X.; Shi, Y.; Klinghofer, V.; Johnson, E.F.; Park, C.H.; Fry, E.H.; Donawho, C.K.; Frost, D.J.; Buchanan, F.G.; Bukofzer, G.T.; Rodriguez, L.E.; Bontcheva-Diaz, V.; Bouska, J.J.; Osterling, D.J.; Olson, A.M.; Marsh, K.C.; Luo, Y.; Giranda, V.L. Optimization of phenyl-substituted benzimidazole carboxamide poly(ADP-ribose) polymerase inhibitors: identification of (S)-2-(2-fluoro-4-(pyrrolidin-2-yl)phenyl)-1H-benzimidazole-4-carboxamide (A-966492), a highly potent and efficacious inhibitor. J. Med. Chem., 2010, 53(8), 3142-3153.
[http://dx.doi.org/10.1021/jm901775y] [PMID: 20337371]
[20]
Kubota, Y.; Iwamoto, T.; Seki, T. The interaction of benzimidazole compounds with DNA: intercalation and groove binding modes. Nuc. Ac. Symp Ser., 1999, 42, 53-54.
[http://dx.doi.org/10.1093/nass/42.1.53]
[21]
(a)Elokdah, H.M.; Chai, S.Y.; Sulkowski, T.S. US Patent, 1998, 5, 764473.
(b)Chem. Abstr., 1998, 129, 58.784g.
[22]
Kilcigil, G.A.; Altanlar, N. Synthesis and antifungal properties of some benzimidazole derivatives. Turk. J. Chem., 2006, 30, 223-228.
[23]
Maruthamuthu D.; Dileepan, B.; Rajam, S.; Venkatraman, B.R.; Stella, C.R.; Ranjith. Synthesis, Characterization and evaluation of biological activity of some novel benzimidazole derivatives. W. J. Pharma. Res., 2015, 4, 1853-1862.
[24]
Rajam, S.; Stella, C.R.; Venkatraman, B.R. Synthesis, characterization and biological evaluation of benzoxazole derivatives. J. Chem. Pharm. Res., 2012, 4, 2988-2993.
[25]
Chandrashekhar, S.; Rajam, S.; Stella, C.R. Maruthamuthu. Synthesis, characterization and antimicrobial activity of N-substituted 2- substituted-benzimidazole derivatives. J. Chem. Pharm. Res., 2012, 4, 4937-4940.
[26]
Bocion, P.F.; Cattanach, C.J.; Eggenberg, P.; Gressel, J.; Hagmann, M-L.; Malkin, S.; Wenger, J. Synthesis and characterization of a group of dihydropyrimido-benzimidazole photosystem II herbicides. Pestic. Biochem. Physiol., 1987, 28, 75-78.
[http://dx.doi.org/10.1016/0048-3575(87)90115-5]
[27]
Yang, J.M.; Chen, C.C. GEMDOCK: a generic evolutionary method for molecular docking. Proteins, 2004, 55(2), 288-304.
[http://dx.doi.org/10.1002/prot.20035] [PMID: 15048822]
[28]
Spasov, A.A.; Yozhitsa, I.N.; Bugaeva, L.I.; Anisimova, V.A. Benzimidazole derivatives: spectrum of pharmacological activity and toxicological properties (a review). Pharm. Chem. J., 1999, 33, 232-243.
[http://dx.doi.org/10.1007/BF02510042]
[29]
Nakano, H.; Inoue, T.; Kawasaki, N.; Miyataka, H.; Matsumoto, H.; Taguchi, T.; Inagaki, N.; Nagai, H.; Satoh, T. Synthesis and biological activities of novel antiallergic agents with 5-lipoxygenase inhibiting action. Bioorg. Med. Chem., 2000, 8(2), 373-380.
[http://dx.doi.org/10.1016/S0968-0896(99)00291-6] [PMID: 10722160]
[30]
Hauel, N.H.; Nar, H.; Priepke, H.; Ries, U.; Stassen, J.M.; Wienen, W. Structure-based design of novel potent nonpeptide thrombin inhibitors. J. Med. Chem., 2002, 45(9), 1757-1766.
[http://dx.doi.org/10.1021/jm0109513] [PMID: 11960487]
[31]
He, Y.; Wu, B.; Yang, J.; Robinson, D.; Risen, L.; Ranken, R.; Blyn, L.; Sheng, S.; Swayze, E.E. 2-piperidin-4-yl-benzimidazoles with broad spectrum antibacterial activities. Bioorg. Med. Chem. Lett., 2003, 13(19), 3253-3256.
[http://dx.doi.org/10.1016/S0960-894X(03)00661-9] [PMID: 12951103]
[32]
Porcari, A.R.; Devivar, R.V.; Kucera, L.S.; Drach, J.C.; Townsend, L.B. Design, synthesis, and antiviral evaluations of 1-(substituted benzyl)-2-substituted-5,6-dichlorobenzimidazoles as nonnucleoside analogues of 2,5,6-trichloro-1-(β-D-ribofuranosyl)benzimidazole. J. Med. Chem., 1998, 41(8), 1252-1262.
[http://dx.doi.org/10.1021/jm970559i] [PMID: 9548815]
[33]
Roth, T.; Morningstar, M.L.; Boyer, P.L.; Hughes, S.H.; Buckheit, R.W., Jr; Michejda, C.J. Synthesis and biological activity of novel nonnucleoside inhibitors of HIV-1 reverse transcriptase. 2-Aryl-substituted benzimidazoles. J. Med. Chem., 1997, 40(26), 4199-4207.
[http://dx.doi.org/10.1021/jm970096g] [PMID: 9435891]
[34]
Migawa, M.T.; Girardet, J.L.; Walker, J.A., II; Koszalka, G.W.; Chamberlain, S.D.; Drach, J.C.; Townsend, L.B. Design, synthesis, and antiviral activity of α-nucleosides: D- and L-isomers of lyxofuranosyl- and (5-deoxylyxofuranosyl)benzimidazoles. J. Med. Chem., 1998, 41(8), 1242-1251.
[http://dx.doi.org/10.1021/jm970545c] [PMID: 9575044]
[35]
Mann, J.; Baron, A.; Opoku-Boahen, Y.; Johansson, E.; Parkinson, G.; Kelland, L.R.; Neidle, S. A new class of symmetric bisbenzimidazole-based DNA minor groove-binding agents showing antitumor activity. J. Med. Chem., 2001, 44(2), 138-144.
[http://dx.doi.org/10.1021/jm000297b] [PMID: 11170623]
[36]
Figge, A.; Altenbach, H.J.; Brauer, J.D.; Tielmann, P. Synthesis and resolution of 2-(2-diphenylphosphinyl-naphthalen-1-yl)-1-isopropyl-1H-benzoimidazole; a new atropisomeric P,N-chelating ligand for asymmetric catalysis. Tetrahedron Asymmetry, 2002, 13, 137-144.
[http://dx.doi.org/10.1016/S0957-4166(02)00079-4]
[37]
Hisano, T.; Ichikawa, M.; Tsumoto, K.; Tasaki, M. Synthesis of benzoxazoles, benzothiazoles and benzimidazoles and evaluation of their antifungal, insecticidal and herbicidal activities. Chem. Pharm. Bull. (Tokyo), 1982, 30, 2996-3004.
[http://dx.doi.org/10.1248/cpb.30.2996]
[38]
Kumar, B.V.S.; Vaidya, S.D.; Kumar, R.V.; Bhirud, S.B.; Mane, R.B. Synthesis and anti-bacterial activity of some novel 2-(6-fluorochroman-2-yl)-1-alkyl/acyl/aroyl-1H-benzimidazoles. Eur. J. Med. Chem., 2006, 41(5), 599-604.
[http://dx.doi.org/10.1016/j.ejmech.2006.01.006] [PMID: 16527375]
[39]
Bhatnagar, I.; George, M.V. Oxidation with metal oxides-II: Oxidation of chalcone phenylhydrazones, pyrazolines, o-aminobenzylidine anils and o-hydroxy benzylidine anils with manganese dioxide. Tetrahedron, 1968, 24, 1293-1298.
[http://dx.doi.org/10.1016/0040-4020(68)88080-9]
[40]
Venkateswarlu, Y.; Kumar, S.R.; Leelavathi, P. Facile and efficient one-pot synthesis of benzimidazoles using lanthanum chloride. Org. Med. Chem. Lett., 2013, 3(1), 7.
[http://dx.doi.org/10.1186/2191-2858-3-7] [PMID: 23919542]
[41]
Weires, N.A.; Boster, J.; Magolan, J. Combined Pd/C and montmorillonite catalysis for one-pot synthesis of benzimidazoles. Eur. J. Org. Chem., 2012, 2012(33), 6508-6512.
[http://dx.doi.org/10.1002/ejoc.201201101] [PMID: 23525858]
[42]
Martins, G.M.; Puccinelli, T.; Gariani, R.A.; Xavier, F.R.; Silveira, C.C.; Mendes, S.R. Facile and efficient aerobic one-pot synthesis of benzimidazoles using Ce(NO3)3·6H2O as promoter. Tetrahedron Lett., 2017, 58, 1969-1972.
[http://dx.doi.org/10.1016/j.tetlet.2017.04.020]
[43]
Bachhav, H.M.; Bhagat, S.B.; Telvekar, V.N. Efficient protocol for the synthesis of quinoxaline, benzoxazole and benzimidazole derivatives using glycerol as green solvent. Tetrahedron Lett., 2011, 52, 5697-5701.
[http://dx.doi.org/10.1016/j.tetlet.2011.08.105]
[44]
Kumar, K.R.; Satyanarayana, P.V.V.; Reddy, B.S. NaHSO4-SiO2 promoted synthesis of Benzimidazole derivatives. Arch. Appl. Sci. Res., 2012, 4, 1517-1521.
[45]
Bhenki, C.; Karhale, S.; Helavi, V. 5-sulfosalicylic acid as an efficient organocatalyst for environmentally benign synthesis of 2-substituted benzimidazoles. Iran. J. Cat., 2016, 6, 409-413.
[46]
Gogoi, P.; Konwar, D. An efficient and one-pot synthesis of imidazolines and benzimidazoles via anaerobic oxidation of carbon–nitrogen bonds in water. Tetrahedron Lett., 2006, 47, 79-82.
[http://dx.doi.org/10.1016/j.tetlet.2005.10.134]
[47]
Singh, M.P.; Sasmal, S.; Lu, W.; Chatterjee, M.N. Synthetic Utility of catalytic fe(iii)/fe(ii) redox cycling towards fused heterocycles: a facile access to substituted benzimidazole, bisbenzimidazole and imidazopyridine derivatives. Synthesis, 2000, 10, 1380-1390.
[http://dx.doi.org/10.1055/s-2000-7111]
[48]
Wang, X-J.; Zhang, L.; Xu, Y.; Murthy, D.; Senanayake, C.H. A practical synthesis of 2-(N-substituted)-aminobenzimidazoles utilizing CuCl-promoted intramolecular cyclization of N-(2-aminoaryl)thioureas. Tetrahedron Lett., 2004, 45, 7167-7170.
[http://dx.doi.org/10.1016/j.tetlet.2004.07.042]
[49]
Alloum, A.B.; Bougrin, K.; Soufiaoui, M. Synthèse chimiosélective des benzimidazoles sur silice traitée par le chlorure du thionyle. Tetrahedron Lett., 2003, 44, 5935-5937.
[http://dx.doi.org/10.1016/S0040-4039(03)01387-X]
[50]
Yang, D.; Fu, H.; Hu, L.; Jiang, Y.; Zhao, Y. Copper-catalyzed synthesis of benzimidazoles via cascade reactions of o-haloacetanilide derivatives with amidine hydrochlorides. J. Org. Chem., 2008, 73(19), 7841-7844.
[http://dx.doi.org/10.1021/jo8014984] [PMID: 18754576]
[51]
Subramanyam, S.C.; Narayanan, S. Yttrium (Iii) Chloride: A Mild and Efficient Catalyst For The Synthesis of Benzimidazoles. Int. J. Apples. Bio. Phar. Tec.h, 2010, 1, 689-694.
[52]
Varala, R.; Nasreen, A.; Enugala, R.; Adapa, R.S. L-Proline catalyzed selective synthesis of 2-aryl-1-arylmethyl-1H-benzimidazoles. Tetrahedron Lett., 2007, 48, 69-72.
[http://dx.doi.org/10.1016/j.tetlet.2006.11.010]
[53]
Wu, C-H.; Sun, C-M. Parallel synthesis of amino bis-benzimidazoles by multistep microwave irradiation. Tetrahedron Lett., 2006, 47, 2601-2604.
[http://dx.doi.org/10.1016/j.tetlet.2006.02.015]
[54]
Surpur, M.P.; Singh, P.R.; Patil, S.B.; Samant, S.D. One-pot synthesis of benzimidazoles from o-nitro anilines under microwaves via a reductive cyclization. Synth. Commun., 2007, 37, 1375-1379.
[http://dx.doi.org/10.1080/00397910701230170]
[55]
Mao, Z.; Wang, Z.; Li, J.; Song, X.; Luo, Y. Rapid and Cheap Synthesis of Benzimidazoles via Intermittent Microwave Promotion: A Simple and Potential Industrial Application of Air as Oxidant. Synth. Commun., 2010, 40, 1963-1977.
[http://dx.doi.org/10.1080/00397910903219328]
[56]
Alibeik, M.A.; Moosavifard, M. FeCl3-doped polyaniline nanoparticles as reusable heterogeneous catalyst for the synthesis of 2-substituted benzimidazoles. Synth. Commun., 2010, 40, 2686-2695.
[http://dx.doi.org/10.1080/00397910903318658]
[57]
Jacob, R.G.; Dutra, L.G.; Radatz, C.S.; Mendes, S.R.; Perin, G.; Lenardão, E.J. Synthesis of 1,2-disubstitued benzimidazoles using SiO2/ZnCl2. Tetrahedron Lett., 2009, 50, 1495-1497.
[http://dx.doi.org/10.1016/j.tetlet.2009.01.076]
[58]
Khan, A.T.; Parvin, T.; Choudhury, L.H. A simple and convenient one-pot synthesis of benzimidazole derivatives using cobalt(II)chloride hexahydrate as catalyst. Synth. Commun., 2009, 39, 2339-2346.
[http://dx.doi.org/10.1080/00397910802654815]
[59]
Narsaiah, V.; Reddy, A.R.; Yadav, J.S. Mild and highly efficient protocol for the synthesis of benzimidazoles using samarium triflate. Synth. Commun., 2011, 41, 262-267.
[http://dx.doi.org/10.1080/00397910903534064]
[60]
Trivedi, R.; De, S.K.; Gibbs, R.A. A convenient one-pot synthesis of 2-substituted benzimidazoles. J. Mol. Catal. Chem., 2006, 245, 8-11.
[http://dx.doi.org/10.1016/j.molcata.2005.09.025]
[61]
Nadaf, R.N.; Siddiqui, S.A.; Daniel, T.; Lahoti, R.J.; Srinivasan, K.V. Room temperature ionic liquid promoted regioselective synthesis of 2-aryl benzimidazoles, benzoxazoles and benzthiazoles under ambient conditions. J. Mol. Catal. A, 2004, 214, 155-160.
[http://dx.doi.org/10.1016/j.molcata.2003.10.064]
[62]
Tandon, V.K.; Kumar, M. BF3-Et2O-promoted one-pot expeditious and convenient synthesis of 2-substituted benzimidazoles and 3,1, 5-benzoxadiazepines. Tetrahedron Lett., 2004, 45, 4185-4187.
[http://dx.doi.org/10.1016/j.tetlet.2004.03.117]
[63]
Heravi, M.M.; Tajbakhsh, M.; Ahmadi, A.N.; Mohajerani, B. Zeolites. efficient and eco-friendly catalysts for the synthesis of benzimidazoles. Monatsh. Chem., 2006, 137, 175-179.
[http://dx.doi.org/10.1007/s00706-005-0407-7]
[64]
Heravi, M.M.; Sadjadi, S.; Oskooie, H.A.; Shoar, R.H.; Bamoharram, F.F. Heteropolyacids as heterogeneous and recyclable catalysts for the synthesis of benzimidazoles. Catal. Commun., 2008, 8, 504-507.
[http://dx.doi.org/10.1016/j.catcom.2007.03.011]
[65]
Khalili, S.B.; Sardarian, A.R. KF/Al2O3: an efficient solid heterogeneous base catalyst in one-pot synthesis of benzimidazoles and bis-benzimidazoles at room temperature. Monatsh. Chem., 2012, 143, 841-846.
[http://dx.doi.org/10.1007/s00706-011-0647-7]
[66]
(a)Candeias, N.R.; Branco, L.C.; Gois, P.M.P.; Afonso, C.A.M.; Trindade, A.F. More sustainable approaches for the synthesis of N-based heterocycles. Chem. Rev., 2009, 109(6), 2703-2802.
(b)Martins, M.A.P.; Frizzo, C.P.; Moreira, D.N.; Buriol, L.; Machado, P. Solvent-free heterocyclic synthesis. Chem. Rev., 2009, 109(9), 4140-4182.
(c)Walsh, P.J.; Li, H.; de Parrodi, C.A. A green chemistry approach to asymmetric catalysis: solvent-free and highly concentrated reactions. Chem. Rev., 2007, 107(6), 2503-2545.
[http://dx.doi.org/10.1021/cr800462w] [PMID: 19385653] [http://dx.doi.org/10.1021/cr9001098] [PMID: 19737022] [http://dx.doi.org/10.1021/cr0509556] [PMID: 17530908]
[67]
Sarmah, M.; Mondal, M. Bora. U. Agro-waste extract based solvents: emergence of novel green solvent for the design of sustainable processes in catalysis and organic chemistry. ChemistrySelect, 2017, 2, 5180-5188.
[http://dx.doi.org/10.1002/slct.201700580]
[68]
(a)Saikia, B.; Borah, P. A new avenue to the Dakin reaction in H2O2-WERSA. RSC Advances, 2015, 5, 105583-105586.
(b)Saikia, E.; Bora, S.J.; Chetia, B.H. 2O2 in WERSA: an efficient green protocol for ipso-hydroxylation of aryl/heteroarylboronic acid. RSC Advances, 2015, 5, 102723-102726.
(c)Godoi, M.; Leitemberger, A.; Böhs, L.M.C.; Silveira, M.V.; Rafique, J.; D’Oca, M.G.M. Rice straw ash extract, an efficient solvent for regioselective hydrothiolation of alkynes. Environ. Chem. Lett., 2019, 17, 1441-1446.
[http://dx.doi.org/10.1039/C5RA20133K] [http://dx.doi.org/10.1039/C5RA21354A] [http://dx.doi.org/10.1007/s10311-019-00882-0]
[69]
Shinde, S.; Damate, S.; Morbale, S.; Patil, M.; Patil, S.S. Aegle marmelos in heterocyclization: greener, highly efficient, one-pot three-component protocol for the synthesis of highly functionalized 4H-benzochromenes and 4H-chromenes. RSC Advances, 2017, 7, 7315-7328.
[http://dx.doi.org/10.1039/C6RA28779D]
[70]
(a)Dewan, A.; Sarmah, M.; Bora, U.; Thakur, A.J. In situ generation of palladium nanoparticles using agro waste and their use as catalyst for copper-, amine-and ligand-free Sonogashira reaction. App. Org. Chem., 2017, 31, e3646.
(b)Sarmah, M.; Dewan, A.; Mondal, M.; Thakur, A.J.; Bora, U. Analysis of the water extract of waste papaya bark ash and its implications as an in situ base in the ligand-free recyclable Suzuki–Miyaura coupling reaction. RSC Advances, 2016, 6, 28981-28985.
[http://dx.doi.org/10.1002/aoc.3646] [http://dx.doi.org/10.1039/C6RA00454G]
[71]
Sarmah, M.; Dewan, A.; Thakur, A.J.; Bora, U. Extraction of Base from Eichhornia crassipes and Its Implication in Palladium-Catalyzed Suzuki Cross-Coupling Reaction. ChemistrySelect, 2017, 2, 7091-7095.
[http://dx.doi.org/10.1002/slct.201701057]
[72]
Kantharaju, K.; Hiremath, P.B. Application of novel, efficient and agro-waste sourced catalyst for Knoevenagel condensation reaction. Indian J. Chem., 2020, 59B, 258-270.
[73]
Hiremath, P.B.; Kantharaju, K. A Microwave accelerated sustainable approach for the synthesis of 2-amino-4h-chromenes catalysed by weppa: a green strategy. Curr. Microw. Chem., 2019, 6, 30-43.
[http://dx.doi.org/10.2174/2213335606666190820091029]
[74]
Hiremath, P.B.; Kantharaju, K. An Efficient and Facile Synthesis of 2-Amino-4H-pyrans & Tetrahydrobenzo[b]pyrans Catalysed by WEMFSA at Room Temperature. ChemistrySelect, 2020, 5, 1896-1906.
[http://dx.doi.org/10.1002/slct.201904336]
[75]
(a)Chia, P.W.; Lim, B.S.; Yong, F.S.J.; Poh, S.C.; Kan, S.Y. An efficient synthesis of bisenols in water extract of waste onion peel ash. Environ. Chem. Lett., 2018, 16, 1493-1499.
(b)Laskar, K.; Bhattacharjee, P.; Gohain, M.; Deka, D.; Bora, U. Application of bio-based green heterogeneous catalyst for the synthesis of arylidinemalononitriles. Sustain. Chem. Pharm., 2019, 14, 100181.
(c)Gohain, M.; Laskar, K.; Phukon, H.; Bora, U.; Kalita, D.; Deka, D. Towards sustainable biodiesel and chemical production: Multifunctional use of heterogeneous catalyst from littered Tectona grandis leaves. Waste Manag., 2020, 102, 212-221.
(d)Gohain, M.; Laskar, K.; Paul, A.K.; Daimary, N.; Maharana, M.; Goswami, I.K.; Deka, D. Carica papaya stem: a source of versatile heterogeneous catalyst for biodiesel production and C–C bond formation. Renew. En., 2020, 147, 541-555.
[http://dx.doi.org/10.1007/s10311-018-0764-1] [http://dx.doi.org/10.1016/j.scp.2019.100181] [http://dx.doi.org/10.1016/j.wasman.2019.10.049] [PMID: 31683077] [http://dx.doi.org/10.1016/j.renene.2019.09.016]
[76]
Isenberg, H.D. Clinical Microbiology Procedures Handbook; Am. Soc. Micro: Washington, D. C, 1992, p. 1.
[77]
(a)Hiremath, P.B.; Kantharaju, K. Zinc dust catalyzed efficient synthesis of 4-arylidene-2-phenyl-5(4H)-oxazolones. Indian J. Chem., 2020, 59B, 1010-1015.
(b)Kantharaju, K.; Hiremath, P.B. CuI-NPs catalyzed mechanochemical assisted n-boc protection of primary amines. Indian J. Chem., 2020, 59B, 1016-1024.
cKantharaju, K.; Hiremath, P.B. A green catalytic system for the Knoevenagel condensation using WEPBA. IJETSR, 2017, 4, 807-813.
[78]
Hiremath, P.B.; Kantharaju, K.; Pattanashetty, S.H. Microwave-assisted synthesis of 4-benzylidene-2-(2-fluorophenyl) oxazol-5(4h)-one derivatives catalysed by egg shell powder and evaluation of their anti-microbial activity In: Conference on Drug Design and Discovery Technologies; 125.Royal Society of Chemistry, 2019; vol. 355, p.
[http://dx.doi.org/10.1039/9781839160783-00123]
[79]
Hiremath, P.B.; Kantharaju, K. Microwave-accelerated facile synthesis of 1h-pyrazolo[1,2-b]phthalazine-5,10-dione derivatives catalyzed by wempa. Polycyc. Arom. Comp., 2020.

Rights & Permissions Print Cite
© 2024 Bentham Science Publishers | Privacy Policy