Green Synthesis of 3-Substituted-4-arylmethylideneisoxazol-5(4H)-one Derivatives Catalyzed by Salicylic Acid

Author(s): Asiyeh Mosallanezhad, Hamzeh Kiyani*.

Journal Name: Current Organocatalysis

Volume 6 , Issue 1 , 2019

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Abstract:

Background: 4-Arylmethylideneisoxazol-5(4H)-ones are a class of organic compounds with a variety of applications in the agriculture, filter dyes, photonic devices, and pharmaceutical industries. They are also used as synthetic precursors for the synthesis of other organic compounds. As a result, efforts are being made to search new and available catalyst and green methods toward their synthesis.

Objective: The aim of this work is to investigate the catalytic activity of salicylic acid as an inexpensive, easy to handle, and safe catalyst to synthesis of some derivatives of isoxazole-5(4H)-ones in water medium.

Methods: To aqueous solution of equal amounts of aryl/heteroaryl aldehydes, β-ketoesters, and hydroxylamine hydrochloride; salicylic acid (15 mol%) was added and the reaction mixture was stirred at room temperature for a specified periods. The precipitated product was filtered and washed with water to obtain 3-substituted-4-arylmethylideneisoxazol-5(4H)-ones. The reaction conditions were also optimized and extended to synthesis other isoxazol-5(4H)-ones.

Results: The salicylic acid is found to possess acceptable catalytic activity for the promotion of three-component cyclocondensation of aryl/heteroaryl aldehydes, β-ketoesters, and hydroxylamine hydrochloride. The three-component reaction led to construction of 3-substituted-4-arylmethylideneisoxazol- 5(4H)-ones in good to high isolated reaction yields.

Conclusion: The efficient and environmental friendliness procedure for the synthesis of isoxazol- 5(4H)-ones is introduced. The reaction also carried out smoothly in water as a cost-effective, simple, green, and non-toxic solvent at room temperature without using heating, microwave, and ultrasound sources.

Keywords: Green synthesis, hydroxylamine hydrochloride, isoxazol-5(4H)-ones, β-keto ester, salicylic acid, water.

[1]
Meng, W.T.; Zheng, Y.; Nie, J.; Xiong, H.Y.; Ma, J.A. Organocatalytic asymmetric one-pot sequential conjugate addition/dearomative fluorination: synthesis of chiral fluorinated isoxazol-5(4H)-ones. J. Org. Chem., 2013, 78, 559-567.
[2]
(a) Wazalwar, S.S.; Banpurkar, A.R.; Perdih, F. Aqueous phase synthesis, crystal structure and biological study of isoxazole extensions of pyrazole-4-carbaldehyde derivatives. J. Mol. Struct., 2017, 1150, 258-267.
(b) Oraby, A.K.; Abdellatif, K.R.A.; Abdelgawad, M.A.; Attia, K.M.; Dawe, L.N.; Georghiou, P.E. 2,4-Disubstituted phenylhydrazonopyrazolone and isoxazolone derivatives as antibacterial agents: synthesis, preliminary biological evaluation and docking studies. Chem. Select, 2018, 3, 3295-3301.
[3]
(a) Banpurkar, A.R.; Wazalwar, S.S.; Perdih, F. Aqueous phase synthesis, crystal structure and antimicrobial activity of 4-(substituted phenylazo)-3-methyl-4H-isoxazol-5-one azo dyes. Bull. Chem. Soc. Ethiop., 2018, 32, 249-257.
(b) Konkala, V.S.; Dubey, P.K. One-pot synthesis of 3-phenyl-4-pyrazolylmethylene-isoxazol-(5H)-ones catalyzed by sodium benzoate in aqueous media under the influence of ultrasound waves: A green chemistry approach. J. Heterocycl. Chem., 2017, 54, 2483-2492.
[4]
Reddy, K.R.; Rao, P.S.; Dev, G.J.; Poornachandra, Y.; Kumar, C.G.; Rao, P.S.; Narsaiah, B. Synthesis of novel 1,2,3-triazole/isoxazole functionalized 2H-Chromene derivatives and their cytotoxic activity. Bioorg. Med. Chem. Lett., 2014, 24, 1661-1663.
[5]
Breuer, S.; Chang, M.W.; Yuan, J.; Torbett, B.E. Identification of HIV-1 inhibitors targeting the nucleocapsid protein. J. Med. Chem., 2012, 55, 4968-4977.
[6]
Kafle, B.; Aher, N.G.; Khadka, D.; Park, H.; Cho, H. Isoxazol-5(4H)one derivatives as PTP1B inhibitors showing an anti-obesity effect. Chem. Asian J., 2011, 6, 2073-2079.
[7]
Tang, M.; Odejinmi, S.I.; Allette, Y.M.; Vankayalapati, H.; Lai, K. Identification of novel small molecule inhibitors of 4-diphosphocytidyl-2-C-methyl-d-erythritol (CDP-ME) kinase of Gram-negative bacteria. Bioorg. Med. Chem., 2011, 19, 5886-5895.
[8]
Kömürcü, Ş.G.; Rollas, S.; Yilmaz, N.; Çevikbaş, A. Synthesis of 3-methyl-4-[(2,4-dihydro-4-substituted-3H-1,2,4-triazole-3-thione-5-yl)phenylhydrazono]-5-isoxazolone and evaluation of their antimicrobial activities. Drug Metabol. Drug Interact., 1995, 12, 161-169.
[9]
(a) Hallenbach, W.; Guth, O.; Seitz, T.; Wrolowsky, H.J.; Desbordes, P.; Wachendorff-Neumann, U.; Dahmen, P.; Voerste, E.; Lösel, P.; Malssm, O.; Rama, R.; Hadano, H. 2012 US Patent, Pub. No.: US 2012/0065063A1;
(b) Hallenbach, W.; Guth, O.; Seitz, T.; Wrolowsky, H.J.; Desbordes, P.; Wachendorff-Neumann, U.; Dahmen, P.; Voerste, E.; Lösel, P.; Malssm, O.; Rama, R.; Hadano, H. 2011 WIPO Patent Application WO/2011/161035A1.
[10]
(a) Ishioka, T.; Kubo, A.; Koiso, Y.; Nagasawa, K.; Itai, A.; Hashimoto, Y. Novel non-steroidal/non-anilide type androgen antagonists with an isoxazolone moiety. Bioorg. Med. Chem., 2002, 10, 1555-1566.
(b) Ishioka, T.; Tanatani, A.; Nagasawa, K.; Hashimoto, Y. Anti-androgens with full antagonistic activity toward human prostate tumor LNCaP cells with mutated androgen receptor. Bioorg. Med. Chem. Lett., 2003, 13, 2655-2658.
[11]
da Silva, A.F.; Fernandes, A.A.G.; Thurow, S.; Stivanin, M.L.; Jurberg, I.D. Isoxazol-5-ones as strategic building blocks in organic synthesis. Synthesis, 2018, 50, 2473-2489.
[12]
Saikh, F.; Das, J.; Ghosh, S. Synthesis of 3-methyl-4-arylmethylene isoxazole-5(4H)-ones by visible light in aqueous ethanol. Tetrahedron Lett., 2013, 54, 4679-4682.
[13]
Kiyani, H.; Ghorbani, F. Potassium phthalimide as efficient basic organocatalyst for the synthesis of 3,4-disubstituted isoxazol-5(4H)-ones in aqueous medium. J. Saudi Chem. Soc., 2017, 21, S112-S119.
[14]
Kiyani, H.; Jabbari, M.; Mosallanezhad, A. Efficient three-component synthesis of 3,4-disubstituted isoxazol-5(4H)-ones in green media. Jordan J. Chem., 2014, 9, 279-288.
[15]
Kiyani, H.; Darbandi, H.; Mosallanezhad, A.; Ghorbani, F. 2-Hydroxy-5-sulfobenzoic acid: An efficient organocatalyst for the three-component synthesis of 1-amidoalkyl-2-naphthols and 3,4-disubstituted isoxazol-5(4H)-ones. Res. Chem. Intermed., 2015, 41, 7561-7579.
[16]
Kiyani, H.; Ghorbani, F.; Kanaani, A.; Ajloo, D.; Vakili, M. N-Bromosuccinimide (NBS)-promoted, three component synthesis of α,β-unsaturated isoxazol-5(4H)-ones, and spectroscopic investigation and computational study of 3-methyl-4-(thiophen-2-ylmethylene)isoxazol-5(4H)-one. Res. Chem. Intermed., 2015, 41, 7739-7773.
[17]
Kiyani, H.; Ghorbani, F. Efficient tandem synthesis of a variety of pyran-annulated heterocycles, 3,4-disubstituted isoxazol-5(4H)-ones, and α,β-unsaturated nitriles catalyzed by potassium hydrogen phthalate in water. Res. Chem. Intermed., 2015, 41, 7847-7882.
[18]
Nakkalwar, S.L. Shivaji, Patwari, B.; Patel, M.M.; Jadhav, V.B. Iodine catalyzed highly efficient one pot three component Synthesis of 4-arylidene-3-methylisoxazol-5(4H)-one in aqueous medium. Curr. Green Chem., 2018, 5, 121-126.
[19]
Kiyani, H.; Samimi, H.A. Nickel-catalyzed one-pot, three-component synthesis of 3,4-disubstituted isoxazole-5(4H)-ones in aqueous medium. Chiang Mai J. Sci., 2017, 44, 1011-1021.
[20]
Kiyani, H.; Ghorbani, F. Expeditious green synthesis of 3,4-disubstituted isoxazole-5(4H)-ones catalyzed by nano-MgO. Res. Chem. Intermed., 2016, 42, 6831-6844.
[21]
Kiyani, H.; Ghorbani, F. Boric acid-catalyzed multi-component reaction for efficient synthesis of 4H-isoxazol-5-ones in aqueous medium. Res. Chem. Intermed., 2015, 41, 2653-2664.
[22]
Kiyani, H.; Mosallanezhad, A. Sulfanilic acid-catalyzed synthesis of 4-arylidene-3-substituted isoxazole-5(4H)-ones. Curr. Org. Synth., 2018, 15, 715-722.
[23]
Mosallanezhad, A.; Kiyani, H. KI-Mediated three-component reaction of hydroxylamine hydrochloride with aaryl/heteroaryl aldehydes and two β-oxoesters. Orbital: Electron. J. Chem., 2018, 10, 133-139.
[24]
Maddila, S.N.; Maddila, S.; van Zyl, W.E.; Jonnalagadda, S.B. Ag/SiO2 as a recyclable catalyst for the facile green synthesis of 3-methyl-4-(phenyl)methylene-isoxazole-5(4H)-ones. Res. Chem. Intermed., 2016, 42, 2553-2566.
[25]
Vekariya, R.H.; Patel, K.D.; Patel, H.D. Fruit juice of citrus limon as a biodegradable and reusable catalyst for facile, eco-friendly and green synthesis of 3,4-disubstituted isoxazol-5(4H)-ones and dihydropyrano [2,3-c]pyrazole derivatives. Res. Chem. Intermed., 2016, 42, 7559-7579.
[26]
Safari, J.; Ahmadzadeh, M.; Zarnegar, Z. Sonochemical synthesis of 3-methyl-4-arylmethylene isoxazole-5(4H)-ones by amine-modified montmorillonite nanoclay. Catal. Commun., 2016, 86, 91-95.
[27]
(a) Liu, Q.; Zhang, Y.N. One-pot synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones catalyzed by sodium benzoate in aqueous media: a green chemistry strategy. Bull. Korean Chem. Soc., 2011, 32, 3559-3560.
(b) Konkala, V.S.; Dubey, P.K. One‐pot synthesis of 3‐phenyl‐4‐pyrazolylmethylene‐isoxazol‐(5H)‐ones catalyzed by sodium benzoate in aqueous media under the influence of ultrasound waves: Agreen chemistry approach. J. Heterocycl. Chem., 2017, 54, 2483-2493.
[28]
Qing, L.; Wu, R.T. Facile synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones catalysed by sodium silicate in an aqueous medium. J. Chem. Res., 2011, 35, 598-599.
[29]
Ahmadzadeh, M.; Zarnegar, Z.; Safari, J. Sonochemical synthesis of methyl-4-(hetero)arylmethylene isoxazole-5(4H)-ones using SnII-montmorillonite. Green Chem. Lett. Rev., 2018, 11, 78-85.
[30]
Rikani, A.B.; Setamdideh, D. One-pot and three-component synthesis of isoxazol-5(4H)-one derivatives in the presence of citric acid. Orient. J. Chem., 2016, 32, 1433-1437.
[31]
Vekariya, R.H.; Patel, H.D. Facile, eco-friendly and one-pot synthesis of 3,4-disubstituted isoxazol-5(4H)-ones using starch solution as a reaction media. Indian J. Chem., 2017, 56B, 890-896.
[32]
Patil, M.S.; Mudalian, C.; Chaturbhuj, G.U. Sulfated polyborate catalyzed expeditious and efficient three-component synthesis of 3-methyl-4-(hetero)arylmethylene isoxazole-5(4H)-ones. Tetrahedron Lett., 2017, 58, 3256-3261.
[33]
Laroum, R.; Debache, A. New eco-friendly procedure for the synthesis of 4-arylmethylene-isoxazol-5(4H)-ones catalyzed by pyridinium p-toluenesulfonate (PPTS) in aqueous medium. Synth. Commun., 2018, 48, 1876-1882.
[34]
Lohar, T.; Kumbhar, A.; Barge, M.; Salunkhe, R. DABCO functionalized dicationic ionic liquid (DDIL): A novel green benchmark in multicomponent synthesis of heterocyclic scaffolds under sustainable reaction conditions. J. Mol. Liq., 2016, 224, 1102-1108.
[35]
Pawar, G.T.; Gadekar, S.P.; Arbad, B.R.; Lande, M.K. Modification, characterization, and catalytic application of mesolite for one pot synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones. Bull. Chem. React. Eng. Catal., 2017, 12, 32-40.
[36]
Liu, Q.; Hou, X. One-pot three-component synthesis of 3-methyl-4-arylmethylene-isoxazol-5(4H)-ones catalyzed by sodium sulfide. Phosphorus Sulfur Silicon Relat. Elem., 2012, 187, 448-453.
[37]
(a) Ablajan, K.; Xiamuxi, H. Efficient one-pot synthesis of β-unsaturated isoxazol-5-ones and pyrazol-5-ones under ultrasonic irradiation. Synth. Commun., 2012, 42, 1128-1136.
(b) Ablajan, K.; Xiamuxi, H. The convenient synthesis of 4-arylmethylidene-4,5-dihydro-3-phenylisoxazol-5-ones. Chin. Chem. Lett., 2011, 22, 151-154.
[38]
Vaidya, S.P.; Shridhar, G.; Ladage, S.; Ravishankar, L. A facile synthesis of isoxazolone derivatives catalyzed by cerium chloride heptahydrate in ethyl lactate as a solvent: A green methodology. Curr. Green Chem., 2016, 3, 160-167.
[39]
Dekamin, M.G.; Peyman, S.Z. Phthalimide-N-oxyl salts: Efficient organocatalysts for facile synthesis of (Z)-3-methyl-4-(arylmethylene)-isoxazole-5(4H)-one derivatives in water. Monatsh. Chem., 2016, 147, 445-450.
[40]
Pourmousavi, S.A.; Fattahi, H.R.; Ghorbani, F.; Kanaani, A. Ajloo. D. A green and efficient synthesis of isoxazol-5(4H)-one derivatives in water and a DFT study. J. Iran. Chem. Soc., 2018, 15, 455-469.
[41]
Farahi, S.; Nowrouzi, N.; Irajzadeh, M. Three-component synthesis of isoxazolone derivatives in the presence of 4-(N,N-dimethylamino)pyridinium acetate as a protic ionic liquid. Iran. J. Sci. Technol. Trans. Sci., 2018, 42, 1881-187.
[42]
Setamdideh, D. One-pot green synthesis of isoxazol-5(4H)-one derivatives using Dowex1-x8OH in water. J. Serb. Chem. Soc., 2016, 81, 971-978.
[43]
Ahad, A.; Farooqui, M. Choline chloride and urea based deep eutectic solvent promoted synthesis of arylmethylidene-isoxazol-5(4H)-ones. Int. J. Chemtech Res., 2017, 10, 269-273.
[44]
Khodja, I.A.; Boulcina, R.; Boumoud, T.; Boumoud, B.; Debache, A. NaH2PO4 catalyzed a three-component 4-arylidene-3-methylisoxazol-5(4H)-ones synthesis in solvent-free conditions. Der Pharma Chem., 2016, 8, 97-101.
[45]
(a) Dasgupta, Q.; Chatterjee, K.; Madras, G. Controlled release of salicylic acid from biodegradable crosslinked polyesters. Mol. Pharm., 2015, 12, 3479-3489.
(b) Clay, M.D.; McLeod, E.J. Detection of salicylic acid in willow bark: An addition to a classic series of experiments in the introductory organic chemistry laboratory. J. Chem. Educ., 2012, 89, 1068-1070.
(c) de Avellar, I.G.J.; Cotta, T.A.P.G.; Neder, A.V.F. Using artificial soil and dry-column flash chromatography to simulate organic substance leaching process: A colorful environmental chemistry experiment. J. Chem. Educ., 2012, 89, 248-253.
(d) Kęszycka, P.K.; Szkop, M.; Gajewska, D. Overall content of salicylic acid and salicylates in food available on the European market. J. Agric. Food Chem., 2017, 65, 11085-11091.
(e) Nordstrom, F.L.; Rasmuson, Å.C. Solubility and melting properties of salicylic acid. J. Chem. Eng. Data, 2006, 51, 1668-1671.
(f) Duthie, G.G.; Wood, A.D. Natural salicylates: foods, functions and disease prevention. Food Funct., 2011, 2, 515-520.
(g) Ellison, A.J.; Raines, R.T. A pendant peptide endows a sunscreen with water-resistance. Org. Biomol. Chem., 2018, 16, 7139-7142; Hu, Y.; Zhao, J.; Li, H.; Wang, X.; Hou, P.; Wang, C.; Li, A.; Chen, L. In vivo detection of salicylic acid in sunflower seedlings under salt stress. RSC Adv., 2018, 8, 23404-23410; Lee, k. S.; Kim, K.J.; Ulrich, J. Supramolecular reaggregation of acetyl salicylic acid-4,4-dipyridyl cocrystals from salicylic acid-4,4-dipyridyl cocrystals. Chem. Eng. Technol., 2016, 39, 1257-1262; Draelos, Z.; Lewis, J.; McHugh, L.; Pellegrino, A.; Popescu, L. Novel retinoid ester in combination with salicylic acid for the treatment of acne. J. Cosmet. Dermatol., 2016, 15, 36-42.
[46]
(a) Lin, F.; Song, Q.; Gao, Y.; Cui, X. A catalyst-free, facile and efficient approach to cyclic esters: Synthesis of 4H-benzo[d][1,3]dioxin4-ones. RSC Advances, 2014, 4, 19856-19860.
(b) He, X.; Li, Y.; Wang, M.; Chen, H.X.; Chen, B.; Liang, H.; Zhang, Y.; Pang, J.; Qiu, L. Highly efficient synthesis of benzodioxins with a 2-site quaternary carbon structure by secondary amine-catalyzed dual Michael cascade reactions. Org. Biomol. Chem., 2018, 16, 5533-5538.
[47]
Luo, J.; Preciado, S.; Larrosa, I. Salicylic acids as readily available starting materials for the synthesis of meta-substituted biaryls. Chem. Commun. , 2015, 51, 3127-3130.
[48]
Sridhar, P.R.; Venkatesh, B.C.; Kalesha, S.; Sudharani, C. The first total synthesis of gobichelin B: A mixed ligand side rophore of Streptomyces sp. NRRL F-4415. Org. Biomol. Chem., 2018, 16, 3732-3740.
[49]
Enchev, D.D. New phosphorus derivatives of salicylic acid. Phosphorus Sulfur Silicon Relat. Elem., 2000, 165, 243-248.
[50]
Ekinci, D.; Şentürk, M.; Küfrevioğlu, Ö.İ. Salicylic acid derivatives: Synthesis, features and usage as therapeutic tools. Expert Opin. Ther. Pat., 2011, 21, 1831-1841.
[51]
Paudyal, M.P.; Wu, L.; Zhang, Z.Y.; Spilling, C.D.; Wong, C.F. A new class of salicylic acid derivatives for inhibiting YopH of Yersinia pestis. Bioorg. Med. Chem., 2014, 22, 6781-6788.
[52]
Turgut, Y.; Azizoglu, M.; Erdogan, A.; Arslan, N.; Hosgoren, H. β-Hydroxyamide derivatives of salicylic acid as organocatalysts for enantioselective reductions of prochiral ketones. Tetrahedron Asymmetry, 2013, 24, 853-859.
[53]
Puttaswamy, N.; Kumar, G.S.P.; Al-Ghorbani, M.; Vigneshwaran, V.; Prabhakar, B.T.; Khanum, S.A. Synthesis and biological evaluation of salicylic acid conjugated isoxazoline analogues on immune cell proliferation and angiogenesis. Eur. J. Med. Chem., 2016, 114, 153-161.
[54]
Paraskevopoulos, G.; Krátky´, M.; Mandíková, J.; Trejtnar, F.; Stolaríková, J.; Pávek, P.; Besra, G.; Vinšová, J. Novel derivatives of nitro-substituted salicylic acids: Synthesis, antimicrobial activity and cytotoxicity. Bioorg. Med. Chem., 2015, 23, 7292-7301.
[55]
LiS. LiH.; CaoX.; Chen,C. Synthesis and bio-evaluation of novel salicylic acid-oriented thiourea derivatives with potential applications in agriculture. Lett. Drug Des. Discov., 2014, 11, 98-103.
[56]
de Boer, J.W.; Alsters, P.L.; Meetsma, A.; Hage, R.; Browne, W.R.; Feringa, B.L. The role of salicylic acid, L-ascorbic acid and oxalic acid in promoting the oxidation of alkenes with H2O2 catalysed by [MnIV2(O)3(tmtacn)2]2+. Dalton Trans., 2008, 6283-6295.
[57]
Khodja, I.A.; Ghalem, W.; Dehimat, Z.I.; Boulcina, R.; Carboni, B.; Debache, A. Solvent-free synthesis of dihydropyridines and acridinediones via a salicylic acid-catalyzed Hantzsch multicomponent reaction. Synth. Commun., 2014, 44, 959-967.
[58]
Liu, M.; Chen, X.; Chen, T.; Xu, Q.; Yin, S.F. Metal-free oxidative para-acylation of unprotected anilines with N-heteroarylmethanes. Org. Biomol. Chem., 2017, 15, 9845-9854.
[59]
Felipe-Blanco, D.; Gonzalez-Gomez, J.C. Salicylic acid‐catalyzed arylation of enol acetates with anilines. Adv. Synth. Catal., 2018, 360, 2773-2778.
[60]
Felipe-Blanco, D.; Alonso, F.; Gonzalez-Gomez, J.C. Salicylic acid-catalyzed one-pot hydrodeamination of aromatic amines by tert-butyl nitrite in tetrahydrofuran. Adv. Synth. Catal., 2017, 359, 2857-2863.
[61]
Chen, H.J.; Lin, Z.Y.; Li, M.Y.; Li, R.J.; Xue, Q.W.; Chung, J.L.; Chen, S.C.; Chen, Y.J. A new, efficient, and inexpensive copper(II)/salicylic acid complex catalyzed Sonogashira-type cross-coupling of haloarenes and iodoheteroarenes with terminal alkynes. Tetrahedron, 2010, 66, 7755-7761.
[62]
Xu, J.; Song, J.; Pispas, S.; Zhang, G. Controlled/living ring-opening polymerization of ɛ-Caprolactonewith salicylic acid as the organocatalyst. J. Polym. Sci. A Polym. Chem., 2014, 52, 1185-1192.
[63]
Wang, Y.M.; Li, T.T.; Liu, G.Q.; Zhang, L.; Duan, L.; Li, L.; Li, Y.M. Cooperative effect in organocatalytic intramolecular hydroamination of unfunctionalized olefins. RSC Advances, 2014, 4, 9517-9521.
[64]
Marandi, G.; Mir, E.; Mollashahi, E. Synthesis of 2,3-dihydroquinazolin-4(1H)-ones using carboxylic acids as catalyst. Curr. Catal., 2018, 7, 217-223.
[65]
Silva, J.F.; Lima, J.A.C.; de Freitas, J.J.R. Freitas, L.P.S.R. Menezes, P.H.; Freitas, J.C.R. A mild, efficient protocol for the synthesis of homoallylic alcohols using potassium allyltrifluoroborate promoted by salicylic acid. Lett. Org. Chem., 2016, 13, 49-57.
[66]
Banari, H.; Kiyani, H.; Pourali, A. Green synthesis of bis(indolyl)methanes catalysed by salicylic acid. Chiang Mai J. Sci., 2018, 45, 413-420.


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Article Details

VOLUME: 6
ISSUE: 1
Year: 2019
Page: [28 - 35]
Pages: 8
DOI: 10.2174/2213337206666190214161332

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