Abstract
Aims & Objective: An efficient procedure for the synthesis of pyrido[2,1-a]isoquinoline derivatives in excellent yields was investigated using catalyst-free multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature. In addition, Diels- Alder reactions of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds under ultrasonic irradiation are investigated in two procedures. The advantages of this procedure compared to report methods are short time of reaction, high yields of product, easy separation of product, clean mixture of reaction and green media for performing reaction. In addition, because of having isoquinoline core in synthesized compounds, in this research antioxidant activity of some synthesized compounds was studied.
Materials and Methods: To a stirred mixture of phthalaldehyde 1 (2 mmol) and methylamine 2 (2 mmol) in water (3 mL) under ultrasonic irradiation was added to activated acetylenic compounds 4 after 20 min. Alkyl bromide 3 and triphenylphosphine 5 react in another pot in water (3 mL) under ultrasonic irradiation for 15 min. After this time, this mixture was added to the first pot. After completion of the reaction, the solid residue was separated by filtration and washed with Et2O to afforded pure title compound 6.
Results: In this work, generation of pyrido[2,1-a]isoquinoline derivatives 6 are performed using phthalaldehyde 1, methylamine 2, α-halo substituted carbonyls 3, activated acetylenic compounds 4 and triphenylphosphine 5 in water under ultrasonic irradiation condition at room temperature in excellent yield at short time.
Conclusion: In summary, multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature produced pyrido[2,1-a]isoquinoline derivatives in excellent yields. Also, Diels-Alder reaction of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds and triphenylphosphine under ultrasonic irradiation is investigated in two procedures. Also, the antioxidant activities of 6a, 6c, 6g and 6i were evaluated by DPPH radical scavenging and ferric reducing power analyzes. The compounds 6a exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ. The chief benefits of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which agree with some principles of green chemistry.
Keywords: Phthalaldehyde, four-component reaction, Alkyl bromide, isoquinoline, triphenylphosphine, diels-alder reactions.
[http://dx.doi.org/10.1021/jm001002x] [PMID: 10956193]
[http://dx.doi.org/10.1021/jm970815r] [PMID: 9719589]
[http://dx.doi.org/10.1021/cc9001185] [PMID: 20085353]
[http://dx.doi.org/10.3184/030823403322656364]
[http://dx.doi.org/10.1021/cc100056p] [PMID: 20515044]
[http://dx.doi.org/10.1016/j.tetlet.2006.06.042]
[http://dx.doi.org/10.2478/s11696-010-0020-z]
[http://dx.doi.org/10.1016/j.catcom.2007.07.024]
[http://dx.doi.org/10.1016/S1350-4177(00)00029-8] [PMID: 11326605]
[http://dx.doi.org/10.1016/S1350-4177(98)00004-2] [PMID: 11270332]
[http://dx.doi.org/10.1016/S0040-4039(01)01395-8]
[http://dx.doi.org/10.1016/S1350-4177(02)00103-7] [PMID: 12457947]
[http://dx.doi.org/10.1016/j.tet.2007.07.018]
[http://dx.doi.org/10.1016/j.tet.2006.11.023]
[http://dx.doi.org/10.1533/9781782420620]
[http://dx.doi.org/10.1007/978-1-4899-1910-6]
[http://dx.doi.org/10.1081/SCC-120002400]
[http://dx.doi.org/10.1016/j.ultsonch.2008.09.003]
[http://dx.doi.org/10.1021/jo980871f]
[http://dx.doi.org/10.1021/ol990067v]
[http://dx.doi.org/10.1021/jo0105540] [PMID: 11722203]
[http://dx.doi.org/10.1021/ol010230y] [PMID: 11796048]
[http://dx.doi.org/10.1021/jo026294j] [PMID: 12558417]
[http://dx.doi.org/10.1021/ol202565j] [PMID: 22066469]
[http://dx.doi.org/10.1021/ol300810p] [PMID: 22512290]
[http://dx.doi.org/10.1021/acs.joc.6b02995] [PMID: 28186415]
[http://dx.doi.org/10.1128/AAC.46.10.3197-3207.2002] [PMID: 12234845]
(b)Kletsas, D.; Li, W.; Han, Z.; Papadopoulos, V. Peripheral-type benzodiazepine receptor (PBR) and PBR drug ligands in fibroblast and fibrosarcoma cell proliferation: role of ERK, c-Jun and ligandactivated PBR-independent pathways. Biochem. Pharmacol., 2004, 67(10), 1927-1932.
[http://dx.doi.org/10.1016/j.bcp.2004.01.021] [PMID: 15130769]
(c)Mach, U.R.; Hackling, A.E.; Perachon, S.; Ferry, S.; Wermuth, C.G.; Schwartz, J-C.; Sokoloff, P.; Stark, H. Development of novel 1,2,3,4-tetrahydroisoquinoline derivatives and closely related compounds as potent and selective dopamine D3 receptor ligands. ChemBioChem, 2004, 5(4), 508-518.
[http://dx.doi.org/10.1002/cbic.200300784] [PMID: 15185375]
(d)Muscarella, D.E.; O’Brien, K.A.; Lemley, A.T.; Bloom, S.E. Reversal of Bcl-2-mediated resistance of the EW36 human B-cell lymphoma cell line to arsenite- and pesticide-induced apoptosis by PK11195, a ligand of the mitochondrial benzodiazepine receptor. Toxicol. Sci., 2003, 74(1), 66-73.
[http://dx.doi.org/10.1093/toxsci/kfg052] [PMID: 12730627]
[http://dx.doi.org/10.1080/10715769900300841] [PMID: 10517532]
(b)Ahmadi, F.; Kadivar, M.; Shahedi, M. Antioxidant activity of Kelussia odoratissima Mozaff. in model and food systems. Food Chem., 2007, 105, 57-64.
[http://dx.doi.org/10.1016/j.foodchem.2007.03.056]
[http://dx.doi.org/10.2165/00126839-200405030-00001] [PMID: 15139774]
[PMID: 12462519]
[http://dx.doi.org/10.1007/s11030-019-09935-6] [PMID: 30830596]
[http://dx.doi.org/10.1016/j.jphotobiol.2015.03.027] [PMID: 25889947]
[http://dx.doi.org/10.1007/s00706-007-0810-3]
[http://dx.doi.org/10.1055/s-2008-1072656]
[http://dx.doi.org/10.1002/hlca.200890123]
[http://dx.doi.org/10.1016/j.cclet.2013.09.016]
[http://dx.doi.org/10.1002/jhet.785]
[http://dx.doi.org/10.1002/hc.20724]
[http://dx.doi.org/10.1080/10426507.2010.515953]
[http://dx.doi.org/10.1055/s-0032-1317078]
[http://dx.doi.org/10.1055/s-0036-1591509]
[http://dx.doi.org/10.1002/jhet.2900]
[http://dx.doi.org/10.1002/jccs.201800199]
[http://dx.doi.org/10.1016/j.tetlet.2015.12.021]
[http://dx.doi.org/10.1007/s11947-009-0196-9]
[http://dx.doi.org/10.1021/jf00018a005]
[http://dx.doi.org/10.1021/jf0103572] [PMID: 11513714]
[http://dx.doi.org/10.1021/jf00039a005]