Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate

Multicomponent reactions are valuable synthetic tools to deliver highly functionalized motifs starting from simple building blocks in only one step and in an atom-economical way. Herein we disclose the structure of a new and unexpected compound, the methyl 5-imino-2-methyl-1,10a-dihydro-5<i>H&...

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Main Authors: Joana Pinto, Artur M. S. Silva, Vera L. M. Silva
Format: Article
Language:English
Published: MDPI AG 2022-09-01
Series:Molbank
Subjects:
Online Access:https://www.mdpi.com/1422-8599/2022/4/M1453
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author Joana Pinto
Artur M. S. Silva
Vera L. M. Silva
author_facet Joana Pinto
Artur M. S. Silva
Vera L. M. Silva
author_sort Joana Pinto
collection DOAJ
description Multicomponent reactions are valuable synthetic tools to deliver highly functionalized motifs starting from simple building blocks in only one step and in an atom-economical way. Herein we disclose the structure of a new and unexpected compound, the methyl 5-imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate, which was formed in the ohmic-heating-assisted multicomponent Hantzsch reaction of 3-formylchromone with methyl acetoacetate and ammonium acetate, in aqueous medium, in the presence of tetrabutylammonium bromide as phase transfer catalyst. The title compound was isolated with no need of chromatographic separation and was analyzed by nuclear magnetic resonance (<sup>1</sup>H and <sup>13</sup>C-NMR, HSQC and HMBC) spectroscopy, mass spectrometry (MS) and high-resolution mass spectrometry (HRMS). Its formation as the main reaction product was observed when the reaction was performed using ohmic heating, which may lead to some speculations about the possible existence of specific effects of ohmic heating in the reactivity pathway because of the passage of an alternating electric current of high frequency within the reaction media, opening new opportunities for further investigations of the potential of this thermal processing method in organic synthesis and reactivity optimization.
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spelling doaj.art-5a4790ba9f9041de99e59346ef8fac4f2023-11-24T16:53:32ZengMDPI AGMolbank1422-85992022-09-0120224M145310.3390/M1453Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylateJoana Pinto0Artur M. S. Silva1Vera L. M. Silva2LAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, PortugalLAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, PortugalLAQV-REQUIMTE, Department of Chemistry, University of Aveiro, 3810-193 Aveiro, PortugalMulticomponent reactions are valuable synthetic tools to deliver highly functionalized motifs starting from simple building blocks in only one step and in an atom-economical way. Herein we disclose the structure of a new and unexpected compound, the methyl 5-imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate, which was formed in the ohmic-heating-assisted multicomponent Hantzsch reaction of 3-formylchromone with methyl acetoacetate and ammonium acetate, in aqueous medium, in the presence of tetrabutylammonium bromide as phase transfer catalyst. The title compound was isolated with no need of chromatographic separation and was analyzed by nuclear magnetic resonance (<sup>1</sup>H and <sup>13</sup>C-NMR, HSQC and HMBC) spectroscopy, mass spectrometry (MS) and high-resolution mass spectrometry (HRMS). Its formation as the main reaction product was observed when the reaction was performed using ohmic heating, which may lead to some speculations about the possible existence of specific effects of ohmic heating in the reactivity pathway because of the passage of an alternating electric current of high frequency within the reaction media, opening new opportunities for further investigations of the potential of this thermal processing method in organic synthesis and reactivity optimization.https://www.mdpi.com/1422-8599/2022/4/M1453multicomponent reactionsHantzsch reaction1,4-dihydropyridines3-formylchromoneohmic heatingaqueous phase synthesis
spellingShingle Joana Pinto
Artur M. S. Silva
Vera L. M. Silva
Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
Molbank
multicomponent reactions
Hantzsch reaction
1,4-dihydropyridines
3-formylchromone
ohmic heating
aqueous phase synthesis
title Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
title_full Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
title_fullStr Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
title_full_unstemmed Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
title_short Methyl 5-Imino-2-methyl-1,10a-dihydro-5<i>H</i>-chromeno[2,3-<i>b</i>]pyridine-3-carboxylate
title_sort methyl 5 imino 2 methyl 1 10a dihydro 5 i h i chromeno 2 3 i b i pyridine 3 carboxylate
topic multicomponent reactions
Hantzsch reaction
1,4-dihydropyridines
3-formylchromone
ohmic heating
aqueous phase synthesis
url https://www.mdpi.com/1422-8599/2022/4/M1453
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AT arturmssilva methyl5imino2methyl110adihydro5ihichromeno23ibipyridine3carboxylate
AT veralmsilva methyl5imino2methyl110adihydro5ihichromeno23ibipyridine3carboxylate