Abstract
Background: Hydrated strontium perchlorate [Sr(ClO4)2.3H2O] acts as a very strong oxidizing and dehydrating agent. Until now, it could not be reported as a catalyst in dehydration mechanism-based organic synthetic reactions. Therefore, it is important to find whether it could be an effective catalyst for one-pot multicomponent reactions (MCRs).
Objective: The main objective of the present work is the development of a novel process for the synthesis of 1,4-dihydropyrimidinones through the one-pot multicomponent strategy using hydrated Sr(ClO4)2 as a catalyst. Furthermore, it includes process optimization, stereoselectivity, and spectroscopic characterization of the synthesized compounds.
Methods: Conventional and microwave-supported synthesis of 1,4-dihydropyrimidinones using 20 mol % of hydrated Sr(ClO4)2 catalyst via the one-pot solvent-free reaction was discovered as a new catalytic MCR methodology. The box-Behnken design approach and advanced analytical techniques were used for process optimization and reaction analysis.
Results: The results confirmed that hydrated Sr(ClO4)2 works as an efficient catalyst for one-pot multicomponent organic synthesis under both conventional and microwave heating. It is an effective catalyst for laboratory synthesis of 1,4-dihydropyrimidinones stereoselectively with moderate to excellent yield without any undesirable effect. Microwave heating provided the desired product within 1-4 minutes. Moreover, this method provides easy isolation of the pure products simply by recrystallization, and without the use of a chromatographic purification method.
Conclusion: The simplicity and neutrality of reaction conditions, easy post-reaction workup, higher satisfactory to excellent yield, effectiveness, the diversity of substrates, etc. render the hydrated Sr(ClO4)2 catalyst-based protocol for the stereoselective synthesis of 1,4-dihydropyrimidinones as a highly efficient method. Furthermore, it has been found to be safe un-der laboratory reaction conditions and no undesirable issues have been faced during the process
Graphical Abstract
[http://dx.doi.org/10.1002/anie.202011253] [PMID: 33048416]
[http://dx.doi.org/10.1002/slct.202000683]
[http://dx.doi.org/10.3390/molecules27010132] [PMID: 35011363]
[http://dx.doi.org/10.1016/j.cogsc.2018.08.009]
[http://dx.doi.org/10.1021/acsomega.2c02449] [PMID: 35811927]
[http://dx.doi.org/10.1016/j.catcom.2016.09.028]
[http://dx.doi.org/10.1016/j.molliq.2019.01.065]
[http://dx.doi.org/10.1038/s41598-022-24364-6] [PMID: 36402805]
[http://dx.doi.org/10.1186/s13065-022-00802-4] [PMID: 35246233]
[http://dx.doi.org/10.1039/D2RA03481F] [PMID: 36199605]
[http://dx.doi.org/10.1038/s41598-022-06759-7] [PMID: 35190576]
[http://dx.doi.org/10.1021/cr9003488] [PMID: 20235581]
[http://dx.doi.org/10.1002/tcr.201600067] [PMID: 27353504]
[http://dx.doi.org/10.1080/10406638.2020.1781203]
[http://dx.doi.org/10.1039/C4RA05244G]
[http://dx.doi.org/10.1039/C5NJ02444G]
[http://dx.doi.org/10.1002/cmdc.202100473] [PMID: 34415107]
[http://dx.doi.org/10.1021/acs.orglett.2c03964] [PMID: 36524759]
[http://dx.doi.org/10.1021/jm960056x] [PMID: 8648598]
[http://dx.doi.org/10.1021/sc5000682]
[http://dx.doi.org/10.1002/cbic.200500005] [PMID: 15912555]
[http://dx.doi.org/10.1155/2021/6664756]
[http://dx.doi.org/10.1021/jm990612y] [PMID: 10893308]
[http://dx.doi.org/10.1021/jm00106a048] [PMID: 1995904]
[http://dx.doi.org/10.1021/jm00095a023] [PMID: 1387168]
[http://dx.doi.org/10.1023/A:1023632419813] [PMID: 12825828]
[http://dx.doi.org/10.3389/fmicb.2022.743213] [PMID: 35369453]
[http://dx.doi.org/10.1016/j.bmcl.2019.126750] [PMID: 31699608]
[http://dx.doi.org/10.1016/j.molstruc.2022.132373]
[http://dx.doi.org/10.2174/221135251302151029111113]
[http://dx.doi.org/10.1016/j.ejmech.2018.06.028] [PMID: 29945100]
[http://dx.doi.org/10.18231/2348-0335.2018.0003]
[http://dx.doi.org/10.1002/cmdc.202200031] [PMID: 35174629]
[http://dx.doi.org/10.1590/0074-02760170452] [PMID: 29924131]
[http://dx.doi.org/10.1021/jo971010u] [PMID: 11671828]
[http://dx.doi.org/10.3390/molecules15042087] [PMID: 20428028]
[http://dx.doi.org/10.1021/ja01107a056]
[http://dx.doi.org/10.1021/ja01190a020] [PMID: 18891839]
[http://dx.doi.org/10.1039/C8RA03626H] [PMID: 35540529]
[http://dx.doi.org/10.1080/17518250802541490]
[http://dx.doi.org/10.1016/j.surfrep.2021.100541]
[http://dx.doi.org/10.2174/1570178617999200812133809]
[http://dx.doi.org/10.1021/jf304970g] [PMID: 23327690]
[http://dx.doi.org/10.3390/molecules25214908] [PMID: 33114074]
[http://dx.doi.org/10.1016/j.tetlet.2018.01.070]
[http://dx.doi.org/10.1070/RCR4988]
[http://dx.doi.org/10.1021/acs.organomet.1c00550]