Solvent-Free Synthesis of Bioactive Heterocycles

Sangeeta      Bajpai; Monika      Kamboj; Surabhi      Singh; Monika      Yadav; Bimal   Krishna   Banik
Abstract

The main emphasis of green chemistry is to reduce environmental pollution. Its main goal is to adopt a cost-effective and harmless strategy for human health and the environment. The green synthetic routes have succeeded in adopting solvent-free conditions as an effective tool for sustainability. Heterocycles are organic compounds that are widely distributed by nature. Many of them possess medicinal and pharmacological properties, as this heterocyclic moiety is found in many drugs. The solvent-free strategies for the Synthesis of bioactive heterocycles are, nowadays, regarded as an important objective. Solvent-free reactions are eco-friendly, cost-effective, and an environmentally benign route in organic transformation methods because of their efficiency, reduced reaction time, and high yields, thereby saving energy. This mini-review focuses on the environmentally benign solvent-free Synthesis of heterocycles and their potential pharmacological applications.
Keywords: Solvent-free synthesis, Bioactive Heterocycles, HClO4-SiO₂ catalyst, Ultrasound, Pharmacological applications, dihydropyrimidines.
Graphical Abstract

[1]
Crabtree, R.H. An organometallic future in green and energy chemistry? Organometallics,  2011, 30(1), 17-19.
 [http://dx.doi.org/10.1021/om1009439]

[2]
Foley, P. Kermanshahi pour, A.; Beach, E.S.; Zimmerman, J.B. Derivation and synthesis of renewable surfactants. Chem. Soc. Rev.,  2012, 41(4), 1499-1518.
 [http://dx.doi.org/10.1039/C1CS15217C] [PMID:  22006024]

[3]
Clark, J.H.; Luque, R.; Matharu, A.S. Green chemistry, biofuels, and biorefinery. Annu. Rev. Chem. Biomol. Eng.,  2012, 3(1), 183-207.
 [http://dx.doi.org/10.1146/annurev-chembioeng-062011-081014] [PMID:  22468603]

[4]
Linthorst, J.A. An overview: Origins and development of green chemistry. Found. Chem.,  2010, 12(1), 55-68.
 [http://dx.doi.org/10.1007/s10698-009-9079-4]

[5]
Baron, M. Towards a greener pharmacy by more eco design. Waste Biomass Valoriz.,  2012, 3(1), 395-407.
 [http://dx.doi.org/10.1007/s12649-012-9146-2]

[6]
Henderson, R.K.; Jiménez-González, C.; Constable, D.J.C.; Alston, S.R.; Inglis, G.G.A.; Fisher, G.; Sherwood, J.; Binks, S.P.; Curzons, A.D. Expanding GSK’s solvent selection guide – embedding sustainability into solvent selection starting at medicinal chemistry. Green Chem.,  2011, 13(4), 854-862.
 [http://dx.doi.org/10.1039/c0gc00918k]

[7]
Kumar, A.; Gupta, G.; Srivastava, S. Functional ionic liquid mediated synthesis (FILMS) of dihydrothiophenes and tacrine derivatives. Green Chem.,  2011, 13(9), 2459-2463.
 [http://dx.doi.org/10.1039/c1gc15410a]

[8]
Wilbon, P.A.; Chu, F.; Tang, C. Progress in renewable polymers from natural terpenes, terpenoids, and rosin. Macromol. Rapid Commun.,  2013, 34(1), 8-37.
 [http://dx.doi.org/10.1002/marc.201200513] [PMID:  23065943]

[9]
Raynaud, J.; Wu, J.Y.; Ritter, T. Iron-catalyzed polymerization of isoprene and other 1,3-dienes. Angew. Chem. Int. Ed.,  2012, 51(47), 11805-11808.
 [http://dx.doi.org/10.1002/anie.201205152] [PMID:  23081805]

[10]
Moseley, J.D.; Kappe, C.O. A critical assessment of the greenness and energy efficiency of microwave-assisted organic synthesis. Green Chem.,  2011, 13(4), 794-806.
 [http://dx.doi.org/10.1039/c0gc00823k]

[11]
Bazureau, J.P.; Paquin, L.; Carrié, D.; L’Helgoual’ch, J.M.; Guihéneuf, S.; Coulibaly, K.W.; Burgy, G.; Komaty, S.; Limanton, E. Microwaves in Organic Synthesis, 3rd ed; Wiley & Sons: Hoboken, New Jersey, 2012. 
 [http://dx.doi.org/10.1002/9783527651313.ch16]

[12]
Zhang, J.; Matta, M.E.; Hillmyer, M.A. Synthesis of sequence-specific vinyl copolymers by Regioselective ROMP of multiply substituted cyclooctenes. ACS Macro Lett.,  2012, 1(12), 1383-1387.
 [http://dx.doi.org/10.1021/mz300535r] [PMID:  35607111]

[13]
Mahato, A.K.; Sahoo, B.M.; Banik, B.K.; Mohanta, B.C. Microwave-assisted synthesis: Paradigm of green chemistry. J. Indian Chem. Soc.,  2018, 95, 1327-1339.
 [http://dx.doi.org/10.5281/zenodo.5652579]

[14]
Baghbanzadeh, M.; Pilger, C.; Kappe, C.O. Rapid nickel-catalyzed Suzuki-Miyaura cross-couplings of aryl carbamates and sulfamates utilizing microwave heating. J. Org. Chem.,  2011, 76(5), 1507-1510.
 [http://dx.doi.org/10.1021/jo1024464] [PMID:  21250707]

[15]
Beach, E.S.; Weeks, B.R.; Stern, R.; Anastas, P.T. Plastics additives and green chemistry. Pure Appl. Chem.,  2013, 85(8), 1611-1624.
 [http://dx.doi.org/10.1351/PAC-CON-12-08-08]

[16]
Mendu, P.; Pragathi, J.; Gyana, K.C. Synthesis, spectral characterization, molecular modelling and biological activity of first row transition metal complexes with schiff base ligand derived from chromone- 3-carbaldehyde and o-aminobenzoic acid. J. Chem. Pharm. Res.,  2011, 3(4), 602-613.

[17]
Vrdoljak, V.; Đilović, I.; Rubčić, M.; Kraljević Pavelić, S.; Kralj, M.; Matković-Čalogović, D.; Piantanida, I.; Novak, P.; Rožman, A.; Cindrić, M. Synthesis and characterisation of thiosemicarbazonato molybdenum(VI) complexes and their in vitro antitumor activity. Eur. J. Med. Chem.,  2010, 45(1), 38-48.
 [http://dx.doi.org/10.1016/j.ejmech.2009.09.021] [PMID:  19815314]

[18]
Sakthilatha, D.; Rajavel, R. The template synthesis, spectral and antibacterial investigation of new N2O2 Donor Schiff Base Cu(II), Ni(II), Co(II), Mn(II) and VO (IV). Complexes Derived from 2-hydroxy acetophenone with 4-chloro-2,6-diaminopyrimidine. J. Chem. Pharm. Res.,  2013, 5(1), 57-63.

[19]
Adnan, D. Synthesis and characterization of schiff bases derived from acetylacetone and their theoretical study. Int. J. Chemtech Res.,  2013, 5, 204-211.

[20]
Mhaldar, S.N.; Mandrekar, K.S.; Gawde, M.K.; Shet, R.V.; Tilve, S.G. Solventless Mechanosynthesis Of Bis(Indolyl). Methanes. Int. J. Rapid Commun. Synth. Org. Chem.,  2019, 49(1), 94-101.
 [http://dx.doi.org/10.1080/00397911.2018.1542732]

[21]
Parameswaran, P.; Majik, M.; Praveen, P. Bis(indolyl)methane Alkaloids: Isolation, bioactivity, and syntheses. Synthesis,  2015, 47(13), 1827-1837.
 [http://dx.doi.org/10.1055/s-0034-1380415]

[22]
Alinezhad, H.; Hagh, H.A. Synthesis of bis–Indolylmethanes, tris–Indolylmethanes and 3, 3′- Diindolyl oxindole derivatives using cellulose sulfuric acid as the biodegradable solid acid catalyst under heterogeneous condition iran. J. Org. Chem.,  2010, 2, 383-389.

[23]
Azizi, N.; Gholibeghlo, E.; Manocheri, Z. Green procedure for the synthesis of bis(indolyl)methanes in water. Sci. Iran.,  2012, 19(3), 574-578.
 [http://dx.doi.org/10.1016/j.scient.2011.11.043]

[24]
Mona, H.S.T. (TiO2) catalysed expedient solventless and mild synthesis of Bis (Indolyl)methanes. Acta Chim. Slov.,  2007, 54, 354-359.

[25]
Vijayakumar, B.; Shakthi, N.D. Ind. J. Adv. Chem. Sci.,  2013, 1, 221-227.

[26]
Mo, L.P.; Ma, Z.C.; Zhang, Z.H. CuBr 2 ‐Catalyzed Synthesis of Bis(indolyl)methanes. Synth. Commun.,  2005, 35(15), 1997-2004.
 [http://dx.doi.org/10.1081/SCC-200066653]

[27]
Zhang, Z.H.; Yin, L.; Wang, Y.M. An efficient and practical approach for the synthesis of bis (Indolyl) Methanes Catalyzed by Zirconium Tetrachloride. Synthesis,  2005, 12, 1949-1954.

[28]
Bandgarand, B.P.; Shaikh, K.A.J. Organic reactions in aqueous media. InF3 catalysed synthesis of bis. methanes in water under mild conditions. ChemInform,  2004, 35, 35.

[29]
Mi, X.; Luo, S.; He, J.; Cheng, J-P. Dy(OTf)3 in ionic liquid: An efficient catalytic system for reactions of indole with aldehydes/ketones or imines. Tetrahedron Lett.,  2004, 45(23), 4567-4570.
 [http://dx.doi.org/10.1016/j.tetlet.2004.04.039]

[30]
Khaligh, N.G.; Mihankhah, T.; Johan, M.R.; Ching, J.J. Two novel binuclear sulfonic-functionalized ionic liquids: Influence of anion and carbon-spacer on catalytic efficiency for one-pot synthesis of bis(indolyl)methanes. J. Mol. Liq.,  2018, 259, 260-273.
 [http://dx.doi.org/10.1016/j.molliq.2018.03.044]

[31]
Ren, Y.M.; Xu, M.D.; Wang, X. PEG1000-Based dicationic acidic ionic liquid/solvent-free conditions: An efficient catalytic system for the synthesis of Bis(Indolyl)methanes. Catalysts,  2017, 7(10), 300.
 [http://dx.doi.org/10.3390/catal7100300]

[32]
Azizi, N.; Manocheri, Z. Eutectic salts promote green synthesis of bis(indolyl) methanes. Res. Chem. Intermed.,  2012, 38(7), 1495-1500.
 [http://dx.doi.org/10.1007/s11164-011-0479-4]

[33]
Bafti, B.; Khabazzadeh, H. Dimethylurea/citric acid as a highly efficient deep eutectic solvent for the multi-component reactions. J. Chem. Sci.,  2014, 126(3), 881-887.
 [http://dx.doi.org/10.1007/s12039-014-0624-x]

[34]
Yadav, U.N.; Shankarling, G.S. Room temperature ionic liquid choline chloride–oxalic acid: A versatile catalyst for acid-catalyzed transformation in organic reactions. J. Mol. Liq.,  2014, 191, 137-141.
 [http://dx.doi.org/10.1016/j.molliq.2013.11.036]

[35]
Seyedi, N.; Khabazzadeh, H.; Saeednia, S. ZnCl 2/urea as a deep eutectic solvent for the preparation of bis(indolyl)methanes under ultrasonic conditions. Synth. React. Inorg. Met.-Org. Nano-Met. Chem.,  2015, 45(10), 1501-1505.
 [http://dx.doi.org/10.1080/15533174.2013.862828]

[36]
Mukherjee, N.; Chatterjee, T.; Ranu, B.C. Reaction under ball-milling: Solvent-, ligand-, and metal-free synthesis of unsymmetrical diaryl chalcogenides. J. Org. Chem.,  2013, 78(21), 11110-11114.
 [http://dx.doi.org/10.1021/jo402071b] [PMID:  24116379]

[37]
Dhumaskar, K.L.; Tilve, S.G. Synthesis of bis (indolyl)methanes under catalyst-free and solvent-free conditions. Green Chem. Lett. Rev.,  2012, 5(3), 353-402.
 [http://dx.doi.org/10.1080/17518253.2011.637967]

[38]
Keri, R.S.; Sasidhar, B.S.; Nagaraja, B.M.; Santos, M.A. Recent progress in the drug development of coumarin derivatives as potent antituberculosis agents. Eur. J. Med. Chem.,  2015, 100, 257-269.
 [http://dx.doi.org/10.1016/j.ejmech.2015.06.017] [PMID:  26112067]

[39]
Stefanachi, A.; Leonetti, F.; Pisani, L.; Catto, M.; Carotti, A. Coumarin: A natural, privileged and versatile scaffold for bioactive compounds. Molecules,  2018, 23(2), 250-283.
 [http://dx.doi.org/10.3390/molecules23020250] [PMID:  29382051]

[40]
Singh, T.P.; Singh, O.M. Bioactive Heterocycles: Synthesis and Biological Evaluation; Ameta, K.L.; Pawar, R.P; Domb, A.J., Ed.; Nova Science Publishers: Hauppauge, New York, 2012. 

[41]
Matos, L.H.S.; Masson, F.T.; Simeoni, L.A.; Homem-de-Mello, M. Biological activity of dihydropyrimidinone (DHPM) derivatives: A systematic review. Eur. J. Med. Chem.,  2018, 143, 1779-1789.
 [http://dx.doi.org/10.1016/j.ejmech.2017.10.073] [PMID:  29133039]

[42]
Vekariya, R.H.; Patel, H.D. Recent advances in the synthesis of coumarin derivatives via knoevenagel condensation: A review. Synth. Commun.,  2014, 44(19), 2756-2788.
 [http://dx.doi.org/10.1080/00397911.2014.926374]

[43]
Medina, F.G.; Marrero, J.G.; Macías-Alonso, M.; González, M.C.; Córdova-Guerrero, I.; Teissier García, A.G.; Osegueda-Robles, S. Coumarin heterocyclic derivatives: Chemical synthesis and biological activity. Nat. Prod. Rep.,  2015, 32(10), 1472-1507.
 [http://dx.doi.org/10.1039/C4NP00162A] [PMID:  26151411]

[44]
Calcio Gaudino, E.; Tagliapietra, S.; Martina, K.; Palmisano, G.; Cravotto, G. Recent advances and perspectives in the synthesis of bioactive coumarins. RSC Advances,  2016, 6(52), 46394-46405.
 [http://dx.doi.org/10.1039/C6RA07071J]

[45]
Biginelli, P. Aldehyde – Urea derivatives of aceto- and oxaloacetic acids. Gazz. Chim. Ital.,  1893, 23, 360-416.

[46]
Kaur, R.; Chaudhary, S.; Kumar, K.; Gupta, M.K.; Rawal, R.K. Recent synthetic and medicinal perspectives of dihydropyrimidinones: A review. Eur. J. Med. Chem.,  2017, 132, 108-134.
 [http://dx.doi.org/10.1016/j.ejmech.2017.03.025] [PMID:  28342939]

[47]
Rathwa, S.K.; Vasava, M.S.; Bhoi, M.N.; Borad, M.A.; Patel, H.D. Recent advances in the synthesis of C-5-substituted analogs of 3,4-dihydropyrimidin-2-ones: A review. Synth. Commun.,  2018, 48(9), 963-994.
 [http://dx.doi.org/10.1080/00397911.2017.1423503]

[48]
Chanu, L.V.; Singh, T.P.; Devi, L.R.; Singh, O.M. Synthesis of bioactive heterocycles using reusable heterogeneous catalyst HClO4 –SiO2 under solvent-free conditions. Green Chem. Lett. Rev.,  2018, 11(3), 352-360.
 [http://dx.doi.org/10.1080/17518253.2018.1510991]

[49]
Singh, T.P.; Bhattarcharya, S.; Singh, O.M. Indium/TFA-catalyzed synthesis of tetracyclic[6,5,5,6]indole ring, via a tandem cycloannulation of β-oxodithioester with tryptamine. Org. Lett.,  2013, 15(8), 1974-1977.
 [http://dx.doi.org/10.1021/ol400644m] [PMID:  23573995]

[50]
Devi, K.A.; Chanu, L.G.; Chanu, I.H.; Singh, O.M. ChemInform Abstract: One-pot synthesis of 1H-Naphtho[2,1-b]pyran derivatives under solvent-free conditions. Lett. Org. Chem.,  2014, 11(10), 743-747.

[51]
Chanu, I.H.; Devi, L.R.; Khumanthem, N.; Singh, N.I.; Kumar, D.; Singh, O.M. Synthesis of functionalized benzo[f]2H-chromenes and evaluation of their antimicrobial activities. Russ. J. Bioorganic Chem.,  2017, 43(2), 177-185.
 [http://dx.doi.org/10.1134/S1068162017020054]

[52]
Lakhan, R.; Singh, O.P.; Singh, J. Studies on 4 (3H)-Quinazolinone derivatives as antimalarials. J. Indian Chem. Soc.,  1987, 64, 316-318.

[53]
Zhang, L.; Gao, Z.; Peng, C.; Bin, Z.Y.; Zhao, D.; Wu, J.; Xu, Q.; Li, J.X. Ultrasound-promoted synthesis and immunosuppressive activity of novel quinazoline derivatives. Mol. Divers.,  2012, 16(3), 579-590.
 [http://dx.doi.org/10.1007/s11030-012-9390-1] [PMID:  22890961]

[54]
Roopan, S.M.; Bharathi, A.; Prabhakarn, A.; Abdul Rahuman, A.; Velayutham, K.; Rajakumar, G.; Padmaja, R.D.; Lekshmi, M.; Madhumitha, G. Efficient phyto-synthesis and structural characterization of rutile TiO2 nanoparticles using Annona squamosa peel extract. Spectrochim. Acta A Mol. Biomol. Spectrosc.,  2012, 98, 86-90.
 [http://dx.doi.org/10.1016/j.saa.2012.08.055] [PMID:  22983203]

[55]
Hosseini-Sarvari, M.; Safary, E.; Jarrahpour, A.; Heiran, R. Synthesis of N-formylated β-lactams using nano-sulfated TiO2 as catalyst under solvent-free conditions. C. R. Chim.,  2012, 15(11-12), 980-987.
 [http://dx.doi.org/10.1016/j.crci.2012.09.014]

[56]
Su, T.T. Drug screening in Drosophila; why, when, and when not? Wiley Interdiscip. Rev. Dev. Biol.,  2019, 8(6), e346.
 [http://dx.doi.org/10.1002/wdev.346] [PMID:  31056843]

[57]
List, A.; Kurtin, S.; Roe, D.J.; Buresh, A.; Mahadevan, D.; Fuchs, D.; Rimsza, L.; Heaton, R.; Knight, R.; Zeldis, J.B. Efficacy of lenalidomide in myelodysplastic syndromes. N. Engl. J. Med.,  2005, 352(6), 549-557.
 [http://dx.doi.org/10.1056/NEJMoa041668] [PMID:  15703420]

[58]
Witzig, T.E.; Vose, J.M.; Zinzani, P.L.; Reeder, C.B.; Buckstein, R.; Polikoff, J.A.; Bouabdallah, R.; Haioun, C.; Tilly, H.; Guo, P.; Pietronigro, D.; Ervin-Haynes, A.L.; Czuczman, M.S. An international phase II trial of single-agent lenalidomide for relapsed or refractory aggressive B-cell non-Hodgkin’s lymphoma. Ann. Oncol.,  2011, 22(7), 1622-1627.
 [http://dx.doi.org/10.1093/annonc/mdq626] [PMID:  21228334]

[59]
McCarthy, P.L.; Owzar, K.; Hofmeister, C.C.; Hurd, D.D.; Hassoun, H.; Richardson, P.G.; Giralt, S.; Stadtmauer, E.A.; Weisdorf, D.J.; Vij, R.; Moreb, J.S.; Callander, N.S.; Van Besien, K.; Gentile, T.; Isola, L.; Maziarz, R.T.; Gabriel, D.A.; Bashey, A.; Landau, H.; Martin, T.; Qazilbash, M.H.; Levitan, D.; McClune, B.; Schlossman, R.; Hars, V.; Postiglione, J.; Jiang, C.; Bennett, E.; Barry, S.; Bressler, L.; Kelly, M.; Seiler, M.; Rosenbaum, C.; Hari, P.; Pasquini, M.C.; Horowitz, M.M.; Shea, T.C.; Devine, S.M.; Anderson, K.C.; Linker, C. Lenalidomide after stem-cell transplantation for multiple myeloma. N. Engl. J. Med.,  2012, 366(19), 1770-1781.
 [http://dx.doi.org/10.1056/NEJMoa1114083] [PMID:  22571201]

[60]
George, W.M.; David, I.S.; Shen-Chu, C.R. Substituted 2-(2,6-dioxopiperidin-3-yl)-phthalimides and 1-oxoisoindolines and method of reducing TNFα levels.  WO Patent 1998054170A1, 1998.

[61]
Chaulet, C.; Croix, C.; Alagille, D.; Normand, S.; Delwail, A.; Favot, L.; Lecron, J.C.; Viaud-Massuard, M.C. Design, synthesis and biological evaluation of new thalidomide analogues as TNF-α and IL-6 production inhibitors. Bioorg. Med. Chem. Lett.,  2011, 21(3), 1019-1022.
 [http://dx.doi.org/10.1016/j.bmcl.2010.12.031] [PMID:  21215621]

[62]
Ponomaryov, Y.; Krasikova, V.; Lebedev, A.; Chernyak, D.; Varacheva, L.; Chernobroviy, A. Scalable and green process for the synthesis of anticancer drug lenalidomide. Chem. Heterocycl. Compd.,  2015, 51(2), 133-138.
 [http://dx.doi.org/10.1007/s10593-015-1670-0]

[63]
Hu, S.; Yuan, L.; Yan, H.; Li, Z. Design, synthesis and biological evaluation of Lenalidomide derivatives as tumor angiogenesis inhibitor. Bioorg. Med. Chem. Lett.,  2017, 27(17), 4075-4081.
 [http://dx.doi.org/10.1016/j.bmcl.2017.07.046] [PMID:  28757066]

[64]
Wang, H.; Xie, Z.; Lu, B.; Zhong, K.; Lu, J.; Liu, J. One-pot method to construct isoindolinones and its application to the synthesis of DWP205109 and intermediate of Lenalidomide. Tetrahedron Lett.,  2021, 74, 153152.
 [http://dx.doi.org/10.1016/j.tetlet.2021.153152]

[65]
Thirunarayanan, G.; Dineshkumar, N.; Rajarajan, M. Solid Acidic Bentonite/FeCl3 Catalysed Solvent-Free Cyclization Of Some Aryl Enones: Synthesis And Assessment Of Antimicrobial Potentials Of Some Aryl Pyrazolines India. World Sci. News,  2019, 117, 14-28.

[66]
Popov, A.B.; Macan, A.M.; Jakopec, S.; Prpić, H.; Hrkać, A.H.; Pavelić, S.K.; Raić-Malić, S. Green solvent-free synthesis of new N -heterocycle-L-ascorbic acid hybrids and their antiproliferative evaluation. Future Med. Chem.,  2022, 14(16), 1187-1202.
 [http://dx.doi.org/10.4155/fmc-2022-0047] [PMID:  35791783]

[67]
Pouramiri, B.; Rabiei, K.; Meshkatalsadat, M.H.; Rashidi, M. Saccharin based ionic liquid: Novel and recyclable catalyst for eco-friendly mechanosynthesis of Biginelli and Hantzcsh heterocycles under solvent-free conditions. J. Mol. Struct.,  2023, 1292, 136013.
 [http://dx.doi.org/10.1016/j.molstruc.2023.136013]

[68]
Dey, N.; Mandal, A.; Jana, R.; Bera, A.; Azad, S.A.; Giri, S.; Ikbal, M.; Samanta, S.; Ikbal, M.; Samanta, S. Recent developments in the solvent-free synthesis of heterocycles. New J. Chem.,  2023, 47(28), 13035-13079.
 [http://dx.doi.org/10.1039/D3NJ01991H]

[69]
Jonnalagadda, S.B.; Banerjee, B. Solvent-Free Synthesis: Bioactive Heterocycles; De Gruyter: Berlin, Germany, 2024. 
 [http://dx.doi.org/10.1515/9783110985467]

[70]
Priyadarshan, A.; Tripathi, G.; Singh, K.A.; Rajkhowa, S.; Kumar, A.; Tiwari, K.V. Solvent-free approaches towards the synthesis of therapeutically important heterocycles. Curr. Green Chem.,  2023, 11(2), 127-147.
 [http://dx.doi.org/10.2174/2213346110666230915163034]

[71]
Patil, P.; Ansari, A.; Tauro, S.J.; Nadar, S. Green recipes for pyrimidine. Curr. Org. Synth.,  2023, 20(6), 678-705.
 [http://dx.doi.org/10.2174/1570179420666220930154257] [PMID:  36200260]

[72]
Shah, D.; Bambharoliya, T.; Patel, D.; Patel, K.; Patel, N.; Nagani, A.; Bhavsar, V.; Mahavar, A.; Patel, A. Sustainable synthesis of Phenazines: A review of green approaches. Curr. Org. Chem.,  2023, 27(13), 1143-1163.
 [http://dx.doi.org/10.2174/0113852728257006230921091216]

[73]
Kamanna, K.; Amaregouda, Y. Water Mediated green method synthesis of bioactive heterocyclic reported between 2012-2021 accelerated by microwave irradiation: A decennary update. Curr. Organocatal.,  2023, 10(3), 160-179.
 [http://dx.doi.org/10.2174/2213337210666230626105521]

[74]
Sahoo, B.M.; Kumar, B.V.V.R.; Panda, K.C.; Sruti, J.; Tiwari, A.; Patra, S. Green and Sustainable technology: Efficient strategy for the synthesis of biologically active pyrimidine derivatives. Curr. Organocatal.,  2022, 9(1), 34-45.
 [http://dx.doi.org/10.2174/2213337208666211006143134]

[75]
Swami, S.; Shrivastava, R.; Sharma, N.; Agarwala, A.; Verma, V.P.; Singh, A.P. An ultrasound-assisted solvent and catalyst-free synthesis of structurally diverse pyrazole centered 1,5-disubstituted tetrazoles via one-pot four-component reaction. Lett. Org. Chem.,  2022, 19(9), 795-802.
 [http://dx.doi.org/10.2174/1570178619666211220094516]

[76]
Patel, A.; Shah, J.; Patel, K.; Patel, K.; Patel, H.; Dobaria, D.; Shah, U.; Patel, M.; Chokshi, A.; Patel, S.; Parekh, N. Ultrasound-assisted one-pot synthesis of tetrahydro pyrimidine derivatives through biginelli condensation: A catalyst free green chemistry approach. Lett. Org. Chem.,  2021, 18(9)
 [http://dx.doi.org/10.2174/1570178617999201105162851]

[77]
Wagh, Y.B.; Tayade, Y.A.; Mahulikar, P.P.; Dalal, D.S. Citric acid promoted green synthesis of bioactive heterocycles. Curr. Green Chem.,  2023, 10(1), 73-91.
 [http://dx.doi.org/10.2174/2213346110666230102120527]

[78]
El Farouki, K.; Kacem, M.; Dib, M.; Ouchetto, H.; Hafid, A.; Khouili, M. A review on the recent progress of Layered Double Hydroxides (LDHs)- based catalysts for heterocyclic synthesis. Curr. Organocatal.,  2023, 10, 749-756.
 [http://dx.doi.org/10.2174/0122133372264682231019101634]

[79]
Banerjee, B. Green synthesis of bioactive heterocycles-Part 1A. Curr. Green Chem.,  2022, 9(3), 124-126.
 [http://dx.doi.org/10.2174/221334610903230102122357]

[80]
Brahmachari, G. Green chemistry-inspired synthetic methodologies for organic molecules of biological relevance. Curr. Green Chem.,  2024, 11(2), 85-86.
 [http://dx.doi.org/10.2174/221334611102240116093922]

[81]
Brahmachari, G.; Karmakar, I.; Mandal, M.; Mandal, B. Ultrasound-assisted catalyst-free knoevenagel condensation of carbonyl compounds with C – H Acids in water. Curr. Green Chem.,  2024, 11(2), 210-220.
 [http://dx.doi.org/10.2174/0122133461268098231004072803]

[82]
Ali, I.; Bhatia, R. Green and eco-friendly synthetic strategies for quinoxaline derivatives. Curr. Green Chem.,  2024, 11(1), 37-49.
 [http://dx.doi.org/10.2174/2213346110666230724123450]

[83]
Patel, K.; Patel, H.; Shah, D.; Patel, D.; Savaliya, N.; Bambharoliya, T.; Shah, A.; Mahavar, A.; Patel, A. Unlocking the Potential: A comprehensive review for the synthesis of benzofuran derivatives. Curr. Green Chem.,  2024, 11(1), 12-36.
 [http://dx.doi.org/10.2174/0122133461272081231102061911]

[84]
Margetic, D. Mechanochemical and Microwave Multistep Organic Reactions. Curr. Green Chem.,  2024, 11(2), 172-193.
 [http://dx.doi.org/10.2174/2213346110666230830125317]
Cite As
Current Organocatalysis

Solvent-Free Synthesis of Bioactive Heterocycles

Abstract

Graphical Abstract
