Synlett, Table of Contents Synlett 2017; 28(10): 1173-1176DOI: 10.1055/s-0036-1558965 letter © Georg Thieme Verlag Stuttgart · New YorkApplication of Triphenylammonium Tricyanomethanide as an Efficient and Recyclable Nanostructured Molten-Salt Catalyst for the Synthesis of N-Benzylidene-2-arylimidazo[1,2-a]pyridin-3-amines Saeed Baghery* a Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran Email: saadybaghery@yahoo.com Email: zolfi@basu.ac.ir Email: mzolfigol@yahoo.com , Mohammad Ali Zolfigol* a Department of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran Email: saadybaghery@yahoo.com Email: zolfi@basu.ac.ir Email: mzolfigol@yahoo.com , Romana Schirhagl b Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, Netherlands , Masoumeh Hasani b Groningen University, University Medical Center Groningen, Antonius Deusinglaan 1, 9713 AV, Groningen, Netherlands c Department of Analytical Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran› Author AffiliationsRecommend Article Abstract Buy Article All articles of this category Abstract Triphenylammonium tricyanomethanide (Ph3NH)[C(CN)3] was synthesized and used as an efficient and recyclable nanostructured molten-salt (NMS) catalyst for the synthesis of N-benzylidene-2-arylimidazo[1,2-a]pyridin-3-amines by the reaction of various (het)aryl aldehydes with trimethylsilyl cyanide and pyridin-2-amine under solvent-free conditions at 50 °C. The NMS catalyst could be simply recycled and reused several times without significant loss of its catalytic activity. Key words Key wordstriphenylammonium tricyanomethanide - imidazopyridines - nanostructured molten salt - aldehydes - pyridinamine - organocatalysis Full Text References References 1 Noble RD, Gin DL. J. Membr. Sci. 2011; 369: 1-1 2 Scovazzo P, Kieft J, Finan D, Noble RD, Koval CA. J. Membr. Sci. 2004; 238: 57-57 3 Bara JE, Gabriel CJ, Lessmann S, Carlisle TK, Finotello A, Gin DL, Noble RD. Ind. Eng. Chem. Res. 2007; 46: 5380-5380 4 Chowdhury S, Mohan RS, Scott JL. Tetrahedron 2007; 63: 2363-2363 5 Hajipour AR, Ghayeb Y, Sheikhan N, Ruoho A. Tetrahedron Lett. 2009; 50: 5649-5649 6 Wasserscheid P, Keim W. Angew. Chem. Int. Ed. 2000; 39: 3772-3772 7 Dupont J, de Souza RF, Suarez PA. Z. Chem. Rev. 2002; 102: 3667-3667 8 Welton T. Chem. Rev. 1999; 99: 2071-2071 9 Seddon KR. J. Chem. Technol. Biotechnol. 1997; 68: 351-351 10 Wilkes JS. Green Chem. 2002; 4: 73-73 11 Wan J, Zheng C.-J, Fung M.-K, Liu X.-K, Lee C.-S, Zhang X.-H. J. Mater. Chem. 2012; 22: 4502-4502 12 Song G, Zhang Y, Li X. Organometallics 2008; 27: 1936-1936 13a John A, Shaikh MM, Ghosh P. Dalton Trans. 2009; 10581-10581 13b Enguehard-Gueiffier C, Gueiffier A. Mini-Rev. Med. Chem. 2007; 7: 888-888 14 Rival Y, Grassy G, Michel G. Chem. Pharm. Bull. 1992; 40: 1170-1170 15 Fisher MH, Lusi A. J. Med. Chem. 1972; 15: 982-982 16 Rival Y, Grassy G, Taudou A, Ecalle R. Eur. J. Med. Chem. 1991; 26: 13-13 17 Hamdouchi C, de Blas J, del Prado M, Gruber J, Heinz BA, Vance L. J. Med. Chem. 1999; 42: 50-50 18 Kaminsky JJ, Doweyko AM. J. Med. Chem. 1999; 40: 427-427 19 Rupert KC, Henry JR, Dodd JH, Wadsworth SA, Cavender DE, Olini GC, Fahmy B, Siekierka JJ. Bioorg. Med. Chem. Lett. 2003; 13: 347-347 20 Hammad M, Mequid A, Ananni ME, Shafik N. Egypt. J. Chem. 1987; 29: 5401-5401 21 Badaway E, Kappe T. Eur. J. Med. Chem. 1995; 30: 327-327 22 Hranjec M, Kralj M, Piantanida I, Sedić M, Šuman L, Pavelić K, Karminski-Zamola G. J. Med. Chem. 2007; 50: 5696-5696 23 Kotovskaya SK, Baskakova ZM, Charushin VN, Chupakhin ON, Belanov EF, Bormotov NI, Balakhnin SM, Serova OA. Pharm. Chem. J. 2005; 39: 574-574 24 Lhassani M, Chavignon O, Chezal J.-M, Teulade J.-C, Chapat J.-P, Snoeck R, Andrei G, Balzarini J, De Clerc E, Gueiffier A. Eur. J. Med. Chem. 1999; 34: 271-271 25 Guchhait SK, Chaudhary V, Madaan C. Org. Biomol. Chem. 2012; 10: 9271-9271 26 Adib M, Sheibani S, Zhu L.-G, Mirzaei P. Tetrahedron Lett. 2008; 49: 5108-5108 27 Adib M, Sheibani S, Bijanzadeh HR, Zhu L.-G. Tetrahedron 2008; 64: 10681-10681 28 Abdollahi-Alibeik M, Rezaeipoor-Anari A. Catal. Sci. Technol. 2014; 4: 1151-1151 29 Venkatesham R, Manjula A, Vittal Rao B. J. Heterocycl. Chem. 2011; 48: 942-942 30a Ohta VM, Masaki M. Bull. Chem. Soc. Jpn. 1960; 33: 1392-1392 30b Mohan DC, Rao SN, Adimurthy S. J. Org. Chem. 2013; 78: 1266-1266 30c Bagdi AK, Santra S, Monir K, Hajra A. Chem. Commun. 2015; 51: 1555-1555 30d Liu P, Fang L.-s, Lei X, Lin G.-q. Tetrahedron Lett. 2010; 51: 4605-4605 30e Pericherla K, Kaswan P, Pandey K, Kumar A. Synthesis 2015; 47: 887-887 30f Zhu D.-J, Liu M.-C, Ding J.-C, Wu H.-Y. J. Braz. Chem. Soc. 2009; 20: 482-482 30g Lei S, Chen GJ, Mai Y, Chen L, Cai H, Tan J, Cao H. Adv. Synth. Catal. 2016; 358: 67-67 30h Wang C, Lei S, Cao H, Qiu S, Liu J, Deng H, Yan C. J. Org. Chem. 2015; 80: 12725-12725 30i Lei S, Mai Y, Yan C, Mao J, Cao H. Org. Lett. 2016; 18: 3582-3582 30j Cao H, Zhan H, Lin Y, Lin X, Du Z, Jiang H. Org. Lett. 2012; 14: 1688-1688 30k Cao H, Liu X, Zhao L, Cen J, Lin J, Zhu O, Fu M. Org. Lett. 2014; 16: 146-146 30l Lei S, Cao H, Chen L, Liu J, Cai H, Tan J. Adv. Synth. Catal. 2015; 357: 3109-3109 31a Zolfigol MA, Afsharnadery F, Baghery S, Salehzadeh S, Maleki F. RSC Adv. 2015; 5: 75555-75555 31b Zolfigol MA, Safaiee M, Afsharnadery F, Bahrami-Nejad N, Baghery S, Salehzadeh S, Maleki F. RSC Adv. 2015; 5: 100546-100546 31c Zolfigol MA, Kiafar M, Yarie M, Taherpour A, Saeidi-Rad M. RSC Adv. 2016; 6: 50100-50100 31d Zolfigol MA, Khazaei A, Alaie S, Baghery S, Maleki F, Bayat Y, Asghari A. RSC Adv. 2016; 6: 58667-58667 32 Triphenylammonium Tricyanomethanide (Ph3NH)[C(CN)3] Ph3N (3 mmol, 0.736 g) was added to a solution of HC(CN)3 (3 mmol, 0.273 g) in H2O (5 mL), and the mixture was stirred for 3 h at 50 °C. The solvent was then evaporated under reduced pressure and the resulting white powder was dried under reduced pressure at 100 °C for 3 h. The white solid was washed with Et2O to remove any unreacted starting materials and then dried under vacuum to give a white solid; yield: 0.979 g (97%); mp >350 °C. IR (KBr): 3377, 3037, 2987, 2228, 2110, 1639, 1474, 1389, 1062, 887 cm–1. 1H NMR (400 MHz, DMSO-d 6): δ = 6.99 (d, J = 8.4 Hz, 6 H, ArH), 7.04 (t, J = 7.4 Hz, 3 H, ArH), 7.31 (t, J = 8.0 Hz, 6 H, ArH), 8.55 (s, 1 H, NH). 13C NMR (100 MHz, DMSO-d 6): δ = 41.9, 123.3, 124.1, 129.9, 166.4, 166.6. MS: m/z = 336.3 [M+]. For full analytical data, see the Supporting Information. N-benzylidene-2-arylimidazo[1,2-a]pyridin-3-amines 4; General Procedure (Ph3NH)[C(CN)3] (1 mol%; 0.0034 g) was added to and mixed with aldehyde 1 (2 mmol), TMSCN (2; 2 mmol; 0.099 g), and pyridin-2-amine (3; 1 mmol; 0.094 g), and the mixture was heated at 50 °C for the appropriate time (Table 3). When the reaction was complete [TLC, hexane–EtOAc (5:2)], the mixture was washed with H2O (10 mL) and filtered to separate the catalyst from the other materials. (The reaction mixture was insoluble in H2O, and the catalyst was soluble in H2O.) The crude product was purified by crystallization from EtOH–H2O (10:1). All products were identified by comparison of their physical data with those reported in the literature; for spectroscopic data, see the Supporting Information. Supplementary Material Supplementary Material Supporting Information
