Visible light induced Knoevenagel condensation: A clean and efficient protocol using aqueous fruit extract of tamarindus indica as catalyst


  • Rammohan Pal Acharya Jagadish Chandra Bose College 1/1B, A. J. C. Bose Road Kolkata 700 020 West Bengal





Visible light induced a highly efficient and environmentally-friendly Knoevenagel condensation of various aliphatic and aromatic aldehydes with malononitrile has been achieved in excellent yield in presence of aqueous tamarind juice. The tamarind juice could be simply prepared from unripe fruit of Tamarindus indica in water and the reactions go to completion within 2-7 min. A plausible mechanism of light induced Knoevenagel condensation reaction catalyzed by tamarind juice was discussed.


Keywords: Knoevenagel condensation, visible light, aqueous tamarind juice, aldehydes, malononitrile.

Author Biography

Rammohan Pal, Acharya Jagadish Chandra Bose College 1/1B, A. J. C. Bose Road Kolkata 700 020 West Bengal

Department of Chemistry

Assistant Professor of Organic Chemistry


Knoevenagel E (1894) Uebereine darstellungsweise der glutar-saure, Berichte der Deutschen Chemischen Gesellschaft 2(27):2345-2346.

Knoevenagel E (1898) Condensationen zwisschen malonester und aldehyden unter dem einfluss von ammoniak und organ-ischen aminen, Chemische Berichte 31(3): 2585-2595.

Jones G (1967) The Knoevenagel condensation, Organic Reactions 15:204-599.

Tietze LF & Beifuss U (1991) The Knoevenagel reaction. In Comprehensive Organic Synthesis, Trost, BM, Ed. Pergamon Press: Oxford, UK, 341-394.

Yu N, Aramini JM, Germann MW & Huang Z (2000) Reactions of salicylaldehydes with alkyl cyanoacetates on the surface of solid catalysts: synthesis of 4H-chromene derivatives, Tetrahedron Letters 41(36): 6993-6996.

Gallos J, Discordia RP, Crispino GA, Li J, Grosso JA, Polniaszek V & True VC (2003) A mild and efficient synthesis of 4-aryl-quinolin-2(1H)-ones via a tandem amidation/Knoevenagel condensation of 2-amino-benzophenones with esters or lactones,Tetrahedron Letters 44(22): 4271-4273.

Xing C & Zhu S (2004) unexpected formation of tetrasubstituted 2, 3-dihydrofurans from the reactions of β-keto polyfluoroalkanesulfones with aldehydes, Journal of Organic Chemistry 69(19): 6486-6488.

Tietze LF & Rackelmann N (2004) Domino reactions in the synthesis of heterocyclic natural products and analogs, Pure and Applied Chemistry 76(11): 1967-1983.

Vijender M, Kishor P & Satyanarayana B (2008) Zirconium tetrachloride-SiO2 catalyzed Knoevenagel condensation: A simple and efficient protocol for the synthesis of substituted electrophilic alkenes, Arkivoc xiii: 122-128.

Rao PS & Venkataratnam RV (1991) Zinc chloride as a new catalyst for Knoevenagel condensation, Tetrahedron Letters 32(41): 5821-5822.

Prajapati D & Sandhu JS (1993) Cadmium iodide as a new catalyst for Knoevenagel condensation, Journal of the Chemical Society, Perkin Transactions 1, 1: 739-740.

Lehnert, W. (1970) Verbesserte variante der Knoevenagel-kondensation mit TiCl4/THF/pyridine (I). alkyliden-und arylidenmalonester bei 0-25ºC, Tetrahedron Letters 11(54): 4723-4724.

Dai G, Shi D, Zhou L & Huaxue Y (1995) Knoevenagel condensation catalysed by potassium fluoride/alumina, Chinese Journal of Applied Chemistry 12(2): 104-108.

Gill C, Pandhare G, Raut R, Gore V & Gholap S (2008) Knoevenagel condensation: A simple and efficient protocol of electrophilic alkenes catalyzed by anhydrous ferric sulphate with remarkable reusability, Bulletin of the Catalysis Society of India 7: 153-157.

[Mogilaiah K & Reddy CS (2003) an efficient Friedlander condensation using sodium fluoride as catalyst in the solid state, Synthetic Communications 33(18): 3131-3134.

Mallouk S, Bougrin K, Laghzizil a & Benhida R (2010) Microwave-assisted and efficient solvent-free Knoevenagel condensation. A sustainable protocol using calcium hydroxyapatite as catalyst, Molecules 15(2): 813-823.

Bhuiyan MMH, Hossain MI, Ashraful M & Mahmud MM (2012) Microwave assisted Knoevenagel condensation: Synthesis and antimicrobial activities of some arylidene-malononitriles, Chemistry Journal 2(1): 30-36.

McNulty J, Steere JA & Wolf S (1998) The ultrasound promoted Knoevenagel condensation of aromatic aldehydes, Tetrahedron Letters 39(44): 8013-8016.

Palmisano G, Tibiletti F, Penoni A, Colombo F, Tollari S, Garella D, Tagliapietra S & Cravotto G (2011) Ultrasound-enhanced one-pot synthesis of 3-(Het)arylmethyl-4-hydroxycoumarins in water, Ultrasonics Sonochemistry 18(2): 652-660.

Pratap UR, Jawale DV, Waghmare RA, Lingampalle DL & Mane RA (2011) Synthesis of 5-arylidene-2,4-thiazolidinediones by Knoevenagel condensation catalyzed by baker’s yeast, New Journal of Chemistry 35(1): 49-51.

Wang C, Guan Z & He Y (2011) Biocatalytic domino reaction: synthesis of 2H-1-benzopyran-2-one derivatives using alkaline protease from Bacillus licheniformis, Green Chemistry 13(8): 2048-2054.

Xia Y, Yang Z-Y, Brossi A & Lee K-H (1999) Asymmetric solid-phase synthesis of (3R,4R)-di-O-cis-acyl 3-carboxyl khellactones, Organic Letters 1(13): 2113-2115.

Guo G, Arvanitis EA, Pottorf RS & Player MP (2003) Solid-phase synthesis of a tyrphostin ether library, Journal of Combinatorial Chemistry 5(4): 408-413.

Ying A-G, Liu L, Wu G-F, Chen X-Z, Ye W-D, Chen J-H & Zhang K-Y (2009) Knoevenagel condensation catalyzed by DBU Bronsted ionic liquid without solvent, Chemical Research in Chinese Universities 25(6): 876-881.

Khan FA, Dash FJ, Satapathy R & Upadhyay SK (2004) Hydrotalcite catalysis in ionic medium: a recyclable reaction system for heterogeneous Knoevenagel and nitroaldol conden-sation, Tetrahedron Letters 45(15): 3055-3058.

Verdia P, Santamarta F & Tojo E (2011) Knoevenagel reaction in [MMIm][MSO4]: synthesis of coumarins,Molecules 16(6): 4379-4388.

Bigi F, Conforti ML, Maggi R, Piccinno a & Sartori G (2000) Clean synthesis in water: uncatalysed preparation of ylidenemalonitriles, Green Chemistry 2(3): 101-103.

Wang S, Ren Z, Cao W & Tong W (2001) The Knoevenagel condensation of aromatic aldehydes with malononitrile or ethyl cyanoacetate in the presence of CTMAB in water, Synthetic Communications 31(5): 673-677.

Oskooie HA, Heravi MM, Derikvand F, Khorasani M & Bamoharram FF (2006) On water: An efficient Knoevenagel condensation using 12-Tungstophoric acid as a reusable green catalyst, Synthetic Communications 36(19): 2819-2823.

Pasha MA & Manjula K (2011) Lithium hydroxide: A simple and an efficient catalyst for Knoevenagel condensation under solvent-free grindstone method, Journal of Saudi Chem-ical Society 15(3): 283-286.

Rong L, Li X, Wang H, Shi D, Tu S & Zhuang Q (2006) Efficient green procedure for the Knoevenagel condensation under solvent-free conditions, Synthetic Communications 36(16): 2407-2412.

Ren Z, Cao W & Tong W (2002) The Knoevenagel con-densation reaction of aromatic aldehydes with malononitrile by grinding in the absence of solvents and catalysts, Synthetic Communications 32(22): 3475-3479.

Okkerse C & Bekkun V (1999) from fossil to green, Green Chemistry 1(2): 107-114.

Anastas PT & Warner JC (2000) Green Chemistry: Theory and Practice, Oxford University Press, New York, USA.

Hoffmann N (2008) photochemical reactions as key steps in organic synthesis, Chemical Reviews 108(3): 1052-1103.

Fagnoni M, Dondi D, Ravelli D & Albini A (2007) Photocatalysis for the formation of the C-C bond, Chemical Reviews 107(6): 2725-2756.

Ghosh S & Das J (2011) A novel photochemical wittig reaction for the synthesis of 2-aryl/alkylbenzofurans, Tetrahedron Letters 52(10): 1112-1116.

Ghosh S, Das J & Chattopadhyay S (2011) A novel light induced Knoevenagel condensation of Meldrum’s acid with aromatic aldehydes in aqueous ethanol, Tetrahedron Letters 52(22): 2869-2872.

Ghosh, S, Das J & Saikh F (2012) A new synthesis of 2-aryl/alkylbenzofurans by visible light stimulated intermolecular sonogashira coupling and cyclization reaction in water, Tetrahedron Letters 53(44): 5883-5886.

Ghosh S, Saikh F, Das J & Pramanik AK (2013) Hantzsch 1,4-dihydropyridine synthesis in aqueous ethanol by visible light, Tetrahedron Letters 54(1): 58-62.

Li C & Chen L (2006) Organic chemistry in water, Chem-ical Society Reviews 35(1): 68-82.

Breslow R (1991) hydrophobic effects on simple organic reactions in water, Accounts of Chemical Research 24(6): 159-164.

Ramesh E & Raghunathan R (2009) Microwave-assisted K-10 montmorillonite clay-mediated Knoevenagel hetero-Diels-Alder reactions: A novel protocol for the synthesis of polycyclic pyrano[2,3,4-kl]xanthenes derivatives, Synthetic Communications 39(4): 613-625.

Habibi D & Marvi O (2006) Montmorillonite KSF and Montmorillonite K-10 clays as efficient catalysts for the solventless synthesis of bismaleimides and bisphthalimides using microwave irradiation, Arkivoc xiii: 8-15.

Chakrabarty M, Mukherjee A, Arima S, Harigaya Y & Pilet G (2009) Expeditious reaction of ninhydrin with active methylene compounds on montmorillonite K 10 clay, Monatshefte Fur Chemie 140(2): 189-197.

Wada S & Suzuki H (2003) Calcite and fluorite as catalyst for the Knoevenagel condensation of malononitrile and methyl cyanoacetate under solvent-free conditions, Tetrahedron Letters 44(2): 399-401.

Zahouily M, Mounir B, Charki H, Mezdar A, Bahlaouan B & Ouammou M (2006) Investigation of the basis catalytic activity of natural phosphates in the Michael condensation, Arkivoc xiii: 178-186.

Zahouily M, Bahlaouan B, Rayadh A & Sebti S (2004) Natural phosphates and potassium fluoride doped natural phosphate: efficient catalyst for the construction of a carbon-nitrogen bond, Tetrahedron Letters 45(21): 4135-4138.

Sebti S, Smahi A & Solly A (2002) Natural phosphate doped with potasiuum fluoride and modified with sodium nitrate: efficient catalysts for the Knoevenagel condensation, Tetrahedron Letters 43(10): 1813-1815.

Riadi Y, Mamouni R, Azzalou R, Boulahjar R, Abrouki Y, Haddad ME, Routier S, Guillaumet G & Lazar S (2010) Animal bone meal as an efficient catalyst for crossed-aldol condensation, Tetrahedron Letters 51(51): 6715-6717.

Deshmukh MB, Patil SS, Jadhav SD & Pawar PB (2012) Green approach for Knoevenagel condensation of aromatic aldehydes with active methylene group, Synthetic Communica-tions 42(8): 1177-1183.

Patil S, Jadhav SD & Deshmuk MB (2011) Natural acid catalyzed multi-component reaction as a green approach, Archives Apllied Science Research 3(1): 203-208.

Sachdeva H, Saroj R, Khaturia S & Dwivedi D (2013) Environ-economic synthesis and characterization of some new 1,2,4-triazole derivative as organic fluorescent materials and potent fungicidal agents, Organic Chemistry International Article ID 659107: 19 pages.

Patil S, Jhadav SD & Patil UP (2012) Natural acid cata-lyzed synthesis of Schiff base under solvent-free condition: As a green approach, Archives of Apllied Science Research 4(2): 1074-1078.

Pal R, Khasnobis S & Sarkar T (2013) First application of fruit juice of Citrus limon for facile and green synthesis of bis- and tris(indolyl)methanes in water, Chemistry Journal 3(1): 7-12.

Pal R (2013) Microwave-assisted eco-friendly synthesis of bis-, tris(indolyl)methanes and synthesis of di-bis(indolyl)methanes catalyzed by fruit juice of Citrus limon under solvent-free conditions, IOSR Journal of Applied Chem-istry 3(4): 1-8.

Pal R (2013) New greener alternative for biocondensation of aldehydes and indoles using lemon juice: Formation of bis-, tris-, ans tetraindoles, International Journal of Organic Chemis-try 3(2): 136-142.

Patil S, Jadhav SD & Mane S (2011) Pineapple juice as a natural catalyst: An excellent catalyst for biginelli reaction, Journal of Organic Chemistry 1(3): 125-131.

Patil S, Jadhav SD & Deshmukh MB (2013) Eco-friendly and economic method for Knoevenagel condensation by employing natural catalyst, Indian Journal of Chemistry, Section B 52(8): 1172-1175.

Fonseca AM, Monte FJ, Oliveira MCF, Mattos MCM, Cordell GA, Braz-Filho R & Lemos TLG (2009) Coconut water (Cocos nucifera L.) –A new biocatalyst system for organic synthesis, Journal of Molecular Catalysis B: Enzymatic 57(1-4): 78-82.

Mote K, Pore S, Rashinkar G, Kambale S, Kumbhar A & Salunkhe R (2010) Acacia concinna pods: as a green catalyst for highly efficient synthesis of acylation of amines, Archives of Apllied Science Research 2(3): 74-80.

Pore S, Rashimkar G, Mote K & Salunkhe R (2010) Aqueous extract of the pericarp of sapindus trifoliatus fruits: A novel green catalyst for the aldimine synthesis, Chemistry & Biodiversity 7(7): 1796-1800.

Pal R (2013) A convenient, rapid and eco-friendly synthe-sis of bis-, tris(indolyl)methanes and synthesis of tetraindolyl compounds catalyzed by tamarind juice under microwave irradiation, International Journal of Chemtech Applications 2(3): 26-40.

El-Siddig K, Gunasena HPM, Prasad BA, Pushpakumara DKNG, Ramana KVR, Vijayanand P & Wllliams JT (2006) Fruits for the future 1- Tamarind, Tamarindus indica; Southampton Centre for Underutilised Crops, UK:17-18.

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