How to cite this paper
Kumar, P., Hussain, K & Kumar, A. (2014). Solvent-free synthesis and oxidative aromatization of diethyl-2,6-dimethyl-4-(1-phenyl-3-aryl-1H-pyrazol-4-yl)-1,4-dihydropyridine-3,5-dicarboxylates using hypervalent iodine (III) reagents.Current Chemistry Letters, 3(2), 75-84.
Refrences
1 Chikhale, R.V.; Bhole, R.P.; Khedekar, P.B.; Bhusari, K.P. (2009), Synthesis and pharmacological investigation of 3-(substituted 1-phenylethanone)-4-(substituted phenyl)-1, 2, 3, 4-tetrahydropyrimidine-5-carboxylates. Eur. J. Med. Chem. 44, 3645.
2 Tewari, A. K.; Mishra, A. (2001), Synthesis and anti-inflammatory activities of N4, N5-disubstituted-3-methyl-1H-pyrazolo[3,4-c]pyridazines. Bioorg. Med. Chem. 9, 715.
3 Boger, D. L.; Nakahara, S. (1991), Diels-Alder reactions of N-sulfonyl-1-aza-1,3-butadienes: development of a synthetic approach to the streptonigrone C ring J. Org. Chem. 56, 880.
4 Fletcher, M. D.; Hurst, T. E.; Miles, T. J.; Moody, C. J. (2006), Synthesis of highly-functionalised pyridines via hetero-Diels–Alder methodology: reaction of 3-siloxy-1-aza-1,3-butadienes with electron deficient acetylenes. Tetrahedron 62, 5454.
5 Shan, R.; Howlett, S.E.; Knaus, E.E. (2002), Syntheses, Calcium Channel Agonist?Antagonist Modulation Activities, Nitric Oxide Release, and Voltage-Clamp Studies of 2-Nitrooxyethyl 1,4-Dihydro- 2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)pyridine-5-carboxylate Enantiomers. J. Med. Chem. 45, 955 and references therein.
6 Safak, C.; Simsek, R. (2006), Fused 1,4-Dihydropyridines as Potential Calcium Modulatory Compounds. Mini-Rev. Med. Chem. 6, 747.
7 Adibia, H.; Hajipour, A. R. (2007), A convenient and efficient protocol for oxidative aromatization of Hantzsch 1,4-dihydropyridines using benzyltriphenylphosphonium peroxymonosulfate under almost neutral reaction conditions, Bio. Med. Chem. Lett. 17, 1008–1012.
8 Anniyappan, M.; Muralidharan, D.; Perumal, P. T. (2002), A novel application of the oxidizing properties of urea nitrate and peroxydisulfate-cobalt(II): Aromatization of NAD(P)H model Hantzsch 1,4-dihydropyridines, Tetrahedron 58, 5069–5073.
9 Chai, L.; Zhao, Y.; Sheng, Q.; Liu, Z. Q. (2006) Aromatization of Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines with HIO3 and I2O5 in water, Tetrahedron Lett. 47, 9283-9285.
10 Chen, J. M.; Zeng, X.-M. (2009) B-Cyclodextrin-catalyzed mild aromatization of Hantzsch 1,4-dihydropyridines with o-iodoxybenzoic acid in water/acetone. Synth. Commun. 39, 3521–3526.
11 Eynde, J. J. V.; Delfosse, F.; Mayence, A.; Van Haverbeke, Y. (1995) Old reagents, new results: Aromatization of Hantzsch 1,4-dihydropyridines with manganese dioxide and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Tetrahedron 51, 6511–6516.
12 Filipan-Litvic, M.; Litvic, M.; Vinkovic, V. (2008) An efficient, metal-free, room temperature aromatization of Hantzsch-1,4-dihydropyridines with urea–hydrogen peroxide adduct, catalyzed by molecular iodine. Tetrahedron 64, 5649–5656.
13 Han, B.; Liu, Z.; Liu, Q.; Yang, L.; Liu, Z.; Yu, W. (2006) An efficient aerobic oxidative aromatization of Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines. Tetrahedron 62, 2492–2496.
14 Hashemi, M. M.; Ahmadibeni, Y.; Ghafuri, H. (2003), Aromatization of Hantzsch 1,4-dihydropyridines by hydrogen peroxide in the presence of cobalt(II) acetate. Monatsh Chem. 134, 107–110.
15 Heravi, M. M.; Behbahani, F. K.; Oskooie, H. A.; Shoar, R. H. (2005), Catalytic aromatization of Hantzsch 1,4-dihydropyridines by ferric perchlorate in acetic acid. Tetrahedron Lett. 46, 2775–2777.
16 Heravi, M. M.; Derikvand, F.; Hassan-Pour, S.; Bakhtiari, K.; Bamoharram, F. F.; Oskooie, H. A. (2007), Oxidative aromatization of Hantzsch 1,4-dihydropyridines in the presence of mixed-addenda vanadomolybdophosphate heteropolyacid H6PMo9V3O40. Bio. Med. Chem. Lett. 17, 3305–3309.
17 Yadav, J. S.; Reddy, B. V. S.; Basak, A. K.; Baishya, G.; Narsaiah, A. V. (2006), Iodoxybenzoic Acid (IBX): An Efficient and Novel Oxidizing Agent for the Aromatization of 1,4-Dihydropyridines Synthesis 3, 451-454.
18 Khadilkar, B.; Borkar, S. (1998) Silica gel–supported ferric nitrate: A convenient oxidizing reagent, Synth. Commun. 28, 207-212.
19 Litvic, M.; Cepanec, I.; Filipan, M.; Kos, K.; Bartolincic, A.; Druskovic, V.; Tibi, M. M.; Vinkovic, V. (2005), Mild, selective, and high-yield oxidation of Hantzsch 1,4-dihydropyridines with lead(IV) acetate. Heterocycles 65, 23.
20 Liu, D.; Gui, J.; Wang, C.; Lu, F.; Yang, Y.; Sun, Z (2010) Oxidative aromatization of Hantzsch 1,4-dihydropyridines catalyzed by ferric perchlorate in ionic liquids with air. Synth. Commun. 40, 1004–1008.
21 Liu, Z.; Yu, W.; Yang, L.; Liu, Z.-L. (2007), A novel oxidation–ring contraction of Hantzsch 1,4-dihydropyridines to polysubstituted furans, Tetrahedron Lett. 48, 5321.
22 Memarian, H. R.; Abdoli-Senejani, M. (2008), Ultrasound-assisted photochemical oxidation of unsymmetrically substituted 1,4-dihydropyridines. Ultrason. Sonochem. 15, 110.
23 Memarian, H. R.; Abdoli-Senejani, M.; Tangestaninejad, S. (2006), Photosensitized oxidation of unsymmetrical 1,4-dihydropyridines. J. Iran. Chem. Soc. 3, 285.
24 Moghadam, M.; Nasr-Esfahani, M.; Tangestaninejad, S.; Mirkhani, V. (2006), Mild and efficient oxidation of Hantzsch 1,4-dihydropyridines with sodium periodate catalyzed by a new polystyrene-bound Mn(TPP)Cl. Bioorg. Med. Chem. Lett. 16, 2026.
25 Nasr-Esfahani, M.; Moghadam, M.; Tangestaninejad, S.; Mirkhani, V.; Momeni, A. R. (2006), Rapid and efficient oxidation of Hantzsch 1,4-dihydropyridines with sodium periodate catalyzed by manganese(III) Schiff base complexes. Bioorg. Med. Chem. 14, 2720.
26 Pfister, J. R. (1990), Rapid, high-yield oxidation of Hantzsch-type 1,4-dihydropyridines with ceric ammonium nitrate. Synthesis 689–690.
27 Saini, A.; Kumar, S.; Sandhu, J. S. (2007), New strategy for the oxidation of Hantzsch 1,4-dihydropyridines and dihydropyrido[2,3-d]pyrimidines catalyzed by DMSO under aerobic conditions. Synth. Commun. 37, 2317-2324.
28 Sharma, S. D.; Hazarika, P.; Konwar, D. (2008), A simple, green, and one-pot, four-component synthesis of 1,4-dihydropyridines and their aromatization. Catal. Commun. 9, 709–714.
29 Tamaddon, F.; Razmi, Z. (2011), Oxidation of 1,4-dihydropyrimidines and 3,4-dihydropyrimidin-2(1H)-ones to substituted pyridines and pyrimidinones using Ca(OCl)2 in aqueous media. Synth. Commun. 41, 485–492.
30 Eynde, J. V.; Dorazio, R.; Haverbeke, Y. V. (1994), Potassium permanganate, a versatile reagent for the aromatization of Hantzsch 1,4-dihydropyridines. Tetrahedron 50, 2479–2484.
31 Varma, R. S.; Kumar, D. (1999), Manganese triacetate– mediated oxidation of Hantzsch 1,4-dihydropyridines to pyridines. Tetrahedron Lett. 40, 21–24.
32 Xia, J. J.; Wang, G. W. (2005), One-pot synthesis and aromatization of 1,4-dihydropyridines in refluxing water, Synthesis 2379-2383.
33 Zeynizadeh, B.; Dilmaghani, K. A.; Mirzaei, M. (2007), Mild and convenient method for aromatization of Hantzsch esters of 1,4-dihydropyridines with Ag2O. Acta. Chim. Slov. 54, 366.
34 Karade, N. N.; Gampawar, S. V.; Kondre, J. M.; Shinde, S. V. (2008), An efficient combination of Dess-Martin periodinane with molecular iodine or KBr for the facile oxidative aromatization of Hantzsch 1, 4-dihydropyridines. ARKIVOC xii, 9-16.
35 Cheng, D. P.; Chen, Z. C. (2002), Hypervalent iodine in synthesis 76. An efficient oxidation of 1,4-dihydropyridines to pyridines using iodobenzene diacetate. Synth. Commun. 32, 793-798.
36 Lee, K.H.; Ko, K.Y. (2002), Aromatization of Hantzsch 1,4-Dihydropyridines with [Hydroxy(tosyloxy)iodo]benzene. Bull. Korean Chem. Soc. 23, 1505-1506.
37 Lee, J. W.; Ko, K. Y. (2004), Aromatization of Hantzsch 1,4-Dihydropyridines with a Polymer-supported Hypervalent Iodine Reagent. Bull. Korean Chem. Soc. 25, 19-20.
38 Varma, R. S.; Kumar, D. (1999), Solid state oxidation of 1,4-dihydropyridines to pyridines using phenyliodine(III) bis(trifluoroacetate) or elemental sulfur. J. Chem. Soc. Perkin Trans 1 1755-1757.
39 Kumar, P. (2009), Solid State Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Iodobenzene Diacetate or Hydroxy(tosyloxy)iodobenzene. Chin. J. Chem. 27, 1487-1491.
40 Kumar, P. (2010), A novel, facile, simple and convenient oxidative aromatization of Hantzsch 1,4-dihydropyridines to pyridines using polymeric iodosobenzene with KBr, J. Heterocycl. Chem. 47, 1429–1433.
41 Kumar, P.; Kumar, A. (2010) An Expeditious Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Cetyltrimethylammonium Peroxodisulfate: A Phase Transferring Oxidant. Bull. Korean Chem. Soc. 31, 2299.
42 Kumar, P.; Kumar, A.; Hussain, K. (2012), Iodobenzene diacetate (IBD) catalyzed an quick oxidative aromatization of Hantzsch-1,4-dihydropyridines to pyridines under ultrasonic irradiation Ultrasonics Sonochem. 19, 729.
43 Varvoglis, A. (1997), Chemical transformations induced by hypervalent iodine reagents. Tetrahedron 53, 1179-1255.
44 Wirth, T.; Chiai, M.; Zhdankin, V.V.; Koser, G.F.; Tohma, H.; Kita, Y. (2003), Hypervalent iodine chemistry-modern developments in organic synthesis, Topics in Current Chemistry, Springer, Berlin vol. 224.
45 Zhdankin, V.V.; Stang, P.J. (2008), Chemistry of Polyvalent Iodine. Chem. Rev. 108, 5299.
46 Kumar, D.; Sundaree, M.S.; Patel, G.; Rao, V. S.; Varma, R. S. (2006), Solvent-free facile synthesis of novel ?-tosyloxy B-keto sulfones using [hydroxy(tosyloxy)iodo]benzene. Tetrahedron Lett. 47, 8239.
47 Yusubov, M. S.; Wirth, T. (2005), Solvent-Free Reactions with Hypervalent Iodine Reagents Org. Let. 7, 519 and references cited within.
48 Tanaka, K.; Toda, F. (2000), Solvent-Free Organic Synthesis. Chem. Rev. 100, 1025.
49 Cave, G. W. V.; Raston, C. L.; Scott, J. L. (2001) Recent advances in solventless organic reactions: towards benign synthesis with remarkable versatility Chem. Commun. 2159.
50 Varma, R. S. (1999), Solvent-free organic syntheses. using supported reagents and microwave irradiation, Green Chem. 1, 43.
51 Gupta, R.; Jain, A.; Jain, M.; Joshi, R. (2010) ‘One Pot’ Synthesis of 2-Amino-3-cyano-4,6-diarylpyridines under Ultrasonic Irradiation and Grindstone Technology. Bull. Korean Chem. Soc. 31, 3180.
52 Kumar, P.; Kumar, A.; Mohan, J.; Makrandi, J. K. (2010) Heterocyclic Systems Containing Bridgehead Nitrogen Atom: Synthesis and Evaluation of Biological Activity of Imidazo[2,1-b]-1,3,4-thiadiazolo [2,3-c]-s-triazoles, s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline and bis-(s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b][imidazo[4,5-b]-cyclohexane]-5a,6a-diene). Bull. Korean Chem. Soc. 31, 3304.
53 Kumar, P.; Kumar, S.; Husain, K.; Kumar, A. (2011), An efficient synthesis of pyrazole chalcones under solvent-free conditions at room temperature. Chin. Chem. Lett. 22, 37.
54 Li, J.; Qiu, J.; Li, H.; Zhang, G. (2011), An Efficient, Three-component One-pot Preparation of 1,4-Dihydropyridines Containing Novel Substituted Pyrazole under Sulfamic Acid Catalysis. Chin. J. Chem. 29, 511.
55 Prakash, O. ; Hussain, K. ; Kumar, R.; Wadhwa, D. ; Sharma, C. ; Aneja, K.R. (2011), Synthesis and antimicrobial evaluation of new 1,4-dihydro-4-pyrazolylpyridines and 4-pyrazolylpyridines. Org. Med. Chem. Lett. 1:5 doi:10.1186/2191-2858-1-5.
2 Tewari, A. K.; Mishra, A. (2001), Synthesis and anti-inflammatory activities of N4, N5-disubstituted-3-methyl-1H-pyrazolo[3,4-c]pyridazines. Bioorg. Med. Chem. 9, 715.
3 Boger, D. L.; Nakahara, S. (1991), Diels-Alder reactions of N-sulfonyl-1-aza-1,3-butadienes: development of a synthetic approach to the streptonigrone C ring J. Org. Chem. 56, 880.
4 Fletcher, M. D.; Hurst, T. E.; Miles, T. J.; Moody, C. J. (2006), Synthesis of highly-functionalised pyridines via hetero-Diels–Alder methodology: reaction of 3-siloxy-1-aza-1,3-butadienes with electron deficient acetylenes. Tetrahedron 62, 5454.
5 Shan, R.; Howlett, S.E.; Knaus, E.E. (2002), Syntheses, Calcium Channel Agonist?Antagonist Modulation Activities, Nitric Oxide Release, and Voltage-Clamp Studies of 2-Nitrooxyethyl 1,4-Dihydro- 2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)pyridine-5-carboxylate Enantiomers. J. Med. Chem. 45, 955 and references therein.
6 Safak, C.; Simsek, R. (2006), Fused 1,4-Dihydropyridines as Potential Calcium Modulatory Compounds. Mini-Rev. Med. Chem. 6, 747.
7 Adibia, H.; Hajipour, A. R. (2007), A convenient and efficient protocol for oxidative aromatization of Hantzsch 1,4-dihydropyridines using benzyltriphenylphosphonium peroxymonosulfate under almost neutral reaction conditions, Bio. Med. Chem. Lett. 17, 1008–1012.
8 Anniyappan, M.; Muralidharan, D.; Perumal, P. T. (2002), A novel application of the oxidizing properties of urea nitrate and peroxydisulfate-cobalt(II): Aromatization of NAD(P)H model Hantzsch 1,4-dihydropyridines, Tetrahedron 58, 5069–5073.
9 Chai, L.; Zhao, Y.; Sheng, Q.; Liu, Z. Q. (2006) Aromatization of Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines with HIO3 and I2O5 in water, Tetrahedron Lett. 47, 9283-9285.
10 Chen, J. M.; Zeng, X.-M. (2009) B-Cyclodextrin-catalyzed mild aromatization of Hantzsch 1,4-dihydropyridines with o-iodoxybenzoic acid in water/acetone. Synth. Commun. 39, 3521–3526.
11 Eynde, J. J. V.; Delfosse, F.; Mayence, A.; Van Haverbeke, Y. (1995) Old reagents, new results: Aromatization of Hantzsch 1,4-dihydropyridines with manganese dioxide and 2,3-dichloro-5,6-dicyano-1,4-benzoquinone. Tetrahedron 51, 6511–6516.
12 Filipan-Litvic, M.; Litvic, M.; Vinkovic, V. (2008) An efficient, metal-free, room temperature aromatization of Hantzsch-1,4-dihydropyridines with urea–hydrogen peroxide adduct, catalyzed by molecular iodine. Tetrahedron 64, 5649–5656.
13 Han, B.; Liu, Z.; Liu, Q.; Yang, L.; Liu, Z.; Yu, W. (2006) An efficient aerobic oxidative aromatization of Hantzsch 1,4-dihydropyridines and 1,3,5-trisubstituted pyrazolines. Tetrahedron 62, 2492–2496.
14 Hashemi, M. M.; Ahmadibeni, Y.; Ghafuri, H. (2003), Aromatization of Hantzsch 1,4-dihydropyridines by hydrogen peroxide in the presence of cobalt(II) acetate. Monatsh Chem. 134, 107–110.
15 Heravi, M. M.; Behbahani, F. K.; Oskooie, H. A.; Shoar, R. H. (2005), Catalytic aromatization of Hantzsch 1,4-dihydropyridines by ferric perchlorate in acetic acid. Tetrahedron Lett. 46, 2775–2777.
16 Heravi, M. M.; Derikvand, F.; Hassan-Pour, S.; Bakhtiari, K.; Bamoharram, F. F.; Oskooie, H. A. (2007), Oxidative aromatization of Hantzsch 1,4-dihydropyridines in the presence of mixed-addenda vanadomolybdophosphate heteropolyacid H6PMo9V3O40. Bio. Med. Chem. Lett. 17, 3305–3309.
17 Yadav, J. S.; Reddy, B. V. S.; Basak, A. K.; Baishya, G.; Narsaiah, A. V. (2006), Iodoxybenzoic Acid (IBX): An Efficient and Novel Oxidizing Agent for the Aromatization of 1,4-Dihydropyridines Synthesis 3, 451-454.
18 Khadilkar, B.; Borkar, S. (1998) Silica gel–supported ferric nitrate: A convenient oxidizing reagent, Synth. Commun. 28, 207-212.
19 Litvic, M.; Cepanec, I.; Filipan, M.; Kos, K.; Bartolincic, A.; Druskovic, V.; Tibi, M. M.; Vinkovic, V. (2005), Mild, selective, and high-yield oxidation of Hantzsch 1,4-dihydropyridines with lead(IV) acetate. Heterocycles 65, 23.
20 Liu, D.; Gui, J.; Wang, C.; Lu, F.; Yang, Y.; Sun, Z (2010) Oxidative aromatization of Hantzsch 1,4-dihydropyridines catalyzed by ferric perchlorate in ionic liquids with air. Synth. Commun. 40, 1004–1008.
21 Liu, Z.; Yu, W.; Yang, L.; Liu, Z.-L. (2007), A novel oxidation–ring contraction of Hantzsch 1,4-dihydropyridines to polysubstituted furans, Tetrahedron Lett. 48, 5321.
22 Memarian, H. R.; Abdoli-Senejani, M. (2008), Ultrasound-assisted photochemical oxidation of unsymmetrically substituted 1,4-dihydropyridines. Ultrason. Sonochem. 15, 110.
23 Memarian, H. R.; Abdoli-Senejani, M.; Tangestaninejad, S. (2006), Photosensitized oxidation of unsymmetrical 1,4-dihydropyridines. J. Iran. Chem. Soc. 3, 285.
24 Moghadam, M.; Nasr-Esfahani, M.; Tangestaninejad, S.; Mirkhani, V. (2006), Mild and efficient oxidation of Hantzsch 1,4-dihydropyridines with sodium periodate catalyzed by a new polystyrene-bound Mn(TPP)Cl. Bioorg. Med. Chem. Lett. 16, 2026.
25 Nasr-Esfahani, M.; Moghadam, M.; Tangestaninejad, S.; Mirkhani, V.; Momeni, A. R. (2006), Rapid and efficient oxidation of Hantzsch 1,4-dihydropyridines with sodium periodate catalyzed by manganese(III) Schiff base complexes. Bioorg. Med. Chem. 14, 2720.
26 Pfister, J. R. (1990), Rapid, high-yield oxidation of Hantzsch-type 1,4-dihydropyridines with ceric ammonium nitrate. Synthesis 689–690.
27 Saini, A.; Kumar, S.; Sandhu, J. S. (2007), New strategy for the oxidation of Hantzsch 1,4-dihydropyridines and dihydropyrido[2,3-d]pyrimidines catalyzed by DMSO under aerobic conditions. Synth. Commun. 37, 2317-2324.
28 Sharma, S. D.; Hazarika, P.; Konwar, D. (2008), A simple, green, and one-pot, four-component synthesis of 1,4-dihydropyridines and their aromatization. Catal. Commun. 9, 709–714.
29 Tamaddon, F.; Razmi, Z. (2011), Oxidation of 1,4-dihydropyrimidines and 3,4-dihydropyrimidin-2(1H)-ones to substituted pyridines and pyrimidinones using Ca(OCl)2 in aqueous media. Synth. Commun. 41, 485–492.
30 Eynde, J. V.; Dorazio, R.; Haverbeke, Y. V. (1994), Potassium permanganate, a versatile reagent for the aromatization of Hantzsch 1,4-dihydropyridines. Tetrahedron 50, 2479–2484.
31 Varma, R. S.; Kumar, D. (1999), Manganese triacetate– mediated oxidation of Hantzsch 1,4-dihydropyridines to pyridines. Tetrahedron Lett. 40, 21–24.
32 Xia, J. J.; Wang, G. W. (2005), One-pot synthesis and aromatization of 1,4-dihydropyridines in refluxing water, Synthesis 2379-2383.
33 Zeynizadeh, B.; Dilmaghani, K. A.; Mirzaei, M. (2007), Mild and convenient method for aromatization of Hantzsch esters of 1,4-dihydropyridines with Ag2O. Acta. Chim. Slov. 54, 366.
34 Karade, N. N.; Gampawar, S. V.; Kondre, J. M.; Shinde, S. V. (2008), An efficient combination of Dess-Martin periodinane with molecular iodine or KBr for the facile oxidative aromatization of Hantzsch 1, 4-dihydropyridines. ARKIVOC xii, 9-16.
35 Cheng, D. P.; Chen, Z. C. (2002), Hypervalent iodine in synthesis 76. An efficient oxidation of 1,4-dihydropyridines to pyridines using iodobenzene diacetate. Synth. Commun. 32, 793-798.
36 Lee, K.H.; Ko, K.Y. (2002), Aromatization of Hantzsch 1,4-Dihydropyridines with [Hydroxy(tosyloxy)iodo]benzene. Bull. Korean Chem. Soc. 23, 1505-1506.
37 Lee, J. W.; Ko, K. Y. (2004), Aromatization of Hantzsch 1,4-Dihydropyridines with a Polymer-supported Hypervalent Iodine Reagent. Bull. Korean Chem. Soc. 25, 19-20.
38 Varma, R. S.; Kumar, D. (1999), Solid state oxidation of 1,4-dihydropyridines to pyridines using phenyliodine(III) bis(trifluoroacetate) or elemental sulfur. J. Chem. Soc. Perkin Trans 1 1755-1757.
39 Kumar, P. (2009), Solid State Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Iodobenzene Diacetate or Hydroxy(tosyloxy)iodobenzene. Chin. J. Chem. 27, 1487-1491.
40 Kumar, P. (2010), A novel, facile, simple and convenient oxidative aromatization of Hantzsch 1,4-dihydropyridines to pyridines using polymeric iodosobenzene with KBr, J. Heterocycl. Chem. 47, 1429–1433.
41 Kumar, P.; Kumar, A. (2010) An Expeditious Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Cetyltrimethylammonium Peroxodisulfate: A Phase Transferring Oxidant. Bull. Korean Chem. Soc. 31, 2299.
42 Kumar, P.; Kumar, A.; Hussain, K. (2012), Iodobenzene diacetate (IBD) catalyzed an quick oxidative aromatization of Hantzsch-1,4-dihydropyridines to pyridines under ultrasonic irradiation Ultrasonics Sonochem. 19, 729.
43 Varvoglis, A. (1997), Chemical transformations induced by hypervalent iodine reagents. Tetrahedron 53, 1179-1255.
44 Wirth, T.; Chiai, M.; Zhdankin, V.V.; Koser, G.F.; Tohma, H.; Kita, Y. (2003), Hypervalent iodine chemistry-modern developments in organic synthesis, Topics in Current Chemistry, Springer, Berlin vol. 224.
45 Zhdankin, V.V.; Stang, P.J. (2008), Chemistry of Polyvalent Iodine. Chem. Rev. 108, 5299.
46 Kumar, D.; Sundaree, M.S.; Patel, G.; Rao, V. S.; Varma, R. S. (2006), Solvent-free facile synthesis of novel ?-tosyloxy B-keto sulfones using [hydroxy(tosyloxy)iodo]benzene. Tetrahedron Lett. 47, 8239.
47 Yusubov, M. S.; Wirth, T. (2005), Solvent-Free Reactions with Hypervalent Iodine Reagents Org. Let. 7, 519 and references cited within.
48 Tanaka, K.; Toda, F. (2000), Solvent-Free Organic Synthesis. Chem. Rev. 100, 1025.
49 Cave, G. W. V.; Raston, C. L.; Scott, J. L. (2001) Recent advances in solventless organic reactions: towards benign synthesis with remarkable versatility Chem. Commun. 2159.
50 Varma, R. S. (1999), Solvent-free organic syntheses. using supported reagents and microwave irradiation, Green Chem. 1, 43.
51 Gupta, R.; Jain, A.; Jain, M.; Joshi, R. (2010) ‘One Pot’ Synthesis of 2-Amino-3-cyano-4,6-diarylpyridines under Ultrasonic Irradiation and Grindstone Technology. Bull. Korean Chem. Soc. 31, 3180.
52 Kumar, P.; Kumar, A.; Mohan, J.; Makrandi, J. K. (2010) Heterocyclic Systems Containing Bridgehead Nitrogen Atom: Synthesis and Evaluation of Biological Activity of Imidazo[2,1-b]-1,3,4-thiadiazolo [2,3-c]-s-triazoles, s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b]imidazo[4,5-b]quinoxaline and bis-(s-Triazolo[3,4-b]-1,3,4-thiadiazolo[3,2-b][imidazo[4,5-b]-cyclohexane]-5a,6a-diene). Bull. Korean Chem. Soc. 31, 3304.
53 Kumar, P.; Kumar, S.; Husain, K.; Kumar, A. (2011), An efficient synthesis of pyrazole chalcones under solvent-free conditions at room temperature. Chin. Chem. Lett. 22, 37.
54 Li, J.; Qiu, J.; Li, H.; Zhang, G. (2011), An Efficient, Three-component One-pot Preparation of 1,4-Dihydropyridines Containing Novel Substituted Pyrazole under Sulfamic Acid Catalysis. Chin. J. Chem. 29, 511.
55 Prakash, O. ; Hussain, K. ; Kumar, R.; Wadhwa, D. ; Sharma, C. ; Aneja, K.R. (2011), Synthesis and antimicrobial evaluation of new 1,4-dihydro-4-pyrazolylpyridines and 4-pyrazolylpyridines. Org. Med. Chem. Lett. 1:5 doi:10.1186/2191-2858-1-5.