Crystal structures of 3‐methyl‐2(1<i>H</i>)‐quinoxalinone and three substituted derivatives

Mondieig, D.; Négrier, Philippe; Massip, Stéphane; Léger, J. M.; Jarmoumi, Chakir; Lakhrissi, B.

doi:10.1002/poc.1846

Cited by 4 publications

(2 citation statements)

References 27 publications

(28 reference statements)

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“…The proposed mechanism was based on the isolation of the 4-nitrodiaminobenzene imine intermediate which possessed reduced reactivity for intramolecular cyclisation. This type of reaction was exploited in the literature several times for the synthesis of quinoxalin-2(1 H )-one regioisomers [ 10 , 25 – 26 ].…”

Section: Introductionmentioning

confidence: 99%

Switchable highly regioselective synthesis of 3,4-dihydroquinoxalin-2(1H)ones from o-phenylenediamines and aroylpyruvates

Dobiáš¹,

Ondruš²,

Addová³

et al. 2017

Beilstein J. Org. Chem.

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3-Acylmethylidene-3,4-dihydroquinoxalin-2(1H)-ones are compounds which possess a wide range of physical and pharmaceutical applications. These compounds can be easily prepared by cyclocondensation of o-phenylenediamines and aroylpyruvates. Unsymmetrically substituted o-phenylenediamines can be obtained form regioisomeric mixtures of 3,4-dihydroquinoxalin-2(1H)-ones. It is often quite difficult to get a pure regioisomer and determine its structure without controlling the reaction selectivity and exploitation of complex NMR techniques (HSQC, NOESY, HMBC). This article examines the regioselectivity of the cyclocondensation between six monosubstituted o-phenylenediamines (-OMe, -F, -Cl, -COOH, -CN, -NO2) and the derivatives of p-chlorobenzoylpyruvate (ester or acid) which we studied. Six regioisomeric 3,4-dihydroquinoxalin-2(1H)-one pairs were selectively prepared and characterised. Based on our experiences, a simplified methodology for determining the structure of the regioisomers was proposed. We developed two general and highly selective methodologies starting from the same o-phenylenediamines and activated 4-chlorobenzoylpyruvates (ester or acid) enabling switching of 3,4-dihydroquinoxalin-2(1H)-one regioselectivity in a predictable manner. For comparison, all regioselective cyclocondensations were performed with the same standardized conditions (DMF, rt, 3 days), differing only by the additives p-TsOH or HOBt/DIC (hydroxybenzotriazole/N,N’-diisopropylcarbodiimide). Both selected methods are simple, general and highly regioselective (72–97%). A mechanism for the regioselectivity was also proposed and discussed. This study can be used as a guide when choosing the most optimal reaction conditions for the synthesis of the desired 3,4-dihydroquinoxalin-2(1H)-one regioisomers with the best selectivity. The demonstrated methodologies in this article may also be applied to differently substituted 3,4-dihydroquinoxalin-2(1H)-ones in general, which could expand the synthetic impact of our results.

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Section: Introductionmentioning

confidence: 99%

Switchable highly regioselective synthesis of 3,4-dihydroquinoxalin-2(1H)ones from o-phenylenediamines and aroylpyruvates

Dobiáš¹,

Ondruš²,

Addová³

et al. 2017

Beilstein J. Org. Chem.

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“…Astructural analysis of thecrystalline reaction productshowedthe formation of an unexpected compound, namely ad erivative of quinoxalinone. The crystal structures of other quinoxalinone derivatives featuring a methyl group [3,4], acarboxyl group [5]orapyrrol moiety [6]as substituents on the heterocyclic scaffold have been reported earlier. The title compound is aderivative of quinoxalinone bearing a phenyl group on the scaffold of the heterocyclic ring.…”

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confidence: 99%

Crystal structure of 3-phenylquinoxalin-2(1H)-one, C14H10N2O

Schoultz

Gerber

Hosten

et al. 2015

Zeitschrift Für Kristallographie - New Crystal Structures

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Source of materialThe compound was obtained upon reacting (1H-benzo[d]-imidazol-2-yl)(phenyl)methanone with ReO 2 I(PPh 3 ) 2 in methanol. Crystals suitable for the diffraction study were obtainedupon slowevaporation of thesolvent at ambientconditions. Experimental detailsCarbon-boundHatoms were placed in calculated positions(C-H 0.95 Å) andwereincludedinthe refinement in the riding model approximation, with U iso (H) setto1.2U eq (C). Nitrogen-bound H atomswere placed in calculated positions (N-H 0.88 Å) and were included in the refinement in the riding model approximation, with U iso (H) sett o1 .2U eq (N). Due to the absence of as trong anomalousscatterer,t he Flackp arameter is meaningless. Thus, Friedelopposites (2335pairs)havebeenmerged and the item was removed from the CIF. DiscussionNext to cardiovascular diseases, cancer has become one of the main fatal diseases in industrialized countries. Apart fromclassical surgery,chemo-and radiotherapeutic treatments have entered the arsenal of possible cures for certain types of cancer. All methods, however, suffer from theirown setofproblematic side-effects and, as ac onsequence, the development of radiopharmaceuticals -combining the advantages of chemotherapy as well as radiation methods while at the sametimeavoiding their unique respectiveundesiredside-effects -has been atopic of research [1,2].T ailoring andf ine-tuning of thee nvisionedr adiopharmaceuticals' properties such as lipophilicityand,inparticular, inertness is of paramountimportancewithrespect to possible future in vivo applications in contemporary medicine and requires sound knowledge about structural parameters of the ligands applied if a more heuristic approach in the synthesis is to triumph over pure trial-and-error as it is encountered in this specific field of coordination chemistry up to the present day. In continuation of our interest in rhenium-based coordination compounds that might serve as radiopharmaceuticals,arhenium(V)startingmaterialwas reactedwithaderivative of benzimidazole. Astructural analysis of thecrystalline reaction productshowedthe formation of an unexpected compound, namely ad erivative of quinoxalinone. The crystal structures of other quinoxalinone derivatives featuring a methyl group [3,4], acarboxyl group [5]orapyrrol moiety [6]as substituents on the heterocyclic scaffold have been reported earlier. The title compound is aderivative of quinoxalinone bearing a phenyl group on the scaffold of the heterocyclic ring. The asymmetric unit is comprised of two complete molecules. Both molecules are essentially flat (r.m.s. of all fitted non-hydrogen atoms= 0.0388 Åand 0.0576 Å, respectively) and nearly co-planar as the least-squares planes defined by their respective non-hydrogen atomse nclose an angle of only 0.057(6)°. The O=C-N(H) bond lengths along the intracyclic amide moieties hardly differ in between the two crystallographically independant molecules present in the asymmetric unit with 1.348(3) Åand 1.350(3) Åfor the two C-N bond lengths and 1.241(3) Åf or both C=O bond l...

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The reaction of 6-substituted 4-pyrone-2-carboxylic acids with o-phenylenediamine. Synthesis and structure of 3-(1H-1,5-benzodiazepin-2(3Н)-ylidenemethyl)quinoxalin-2(1H)-ones

Обыденнов

Sosnovskikh

2015

Chem Heterocycl Comp

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Crystal structures of 3‐methyl‐2(1H)‐quinoxalinone and three substituted derivatives

Cited by 4 publications

References 27 publications

Switchable highly regioselective synthesis of 3,4-dihydroquinoxalin-2(1H)ones from o-phenylenediamines and aroylpyruvates

Switchable highly regioselective synthesis of 3,4-dihydroquinoxalin-2(1H)ones from o-phenylenediamines and aroylpyruvates

Crystal structure of 3-phenylquinoxalin-2(1H)-one, C14H10N2O

The reaction of 6-substituted 4-pyrone-2-carboxylic acids with o-phenylenediamine. Synthesis and structure of 3-(1H-1,5-benzodiazepin-2(3Н)-ylidenemethyl)quinoxalin-2(1H)-ones

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