Completely dissimilar: The reactivity of 1-unsubstituted 3-chloroquinoline-2,4-diones with ethylene diamine and ethanolamine to form new molecular rearrangements

3-Chloroquinoline-2,4-diones react with ethanolamine to give 3-hydroxyethylaminoquinoline-2,4-diones. By reacting with isothiocyanic acid, these compounds cyclize to form thioxoimidazo derivatives. If a benzyl group is attached to carbon atom C-3, it is cleaved off. Simultaneously, molecular rearrangement proceeds through the formation of compounds with quinazoline skeletons. However, when using ethylene diamine, the compounds are subject to new types of molecular rearrangement leading to the formation of new quinazoline derivatives. © AUTHOR(S)TBU in Zlin [IGA/FT/2019/010

New mono- and diesters with imidazoquinolinone ring- synthesis, structure characterization, and molecular modeling

The objective of the studies was to synthesize and characterize new mono- and diesters with an imidazoquinolin-2-one ring with the use of 2,3-dihydro-2-thioxo-1H-imidazo[4,5-c]-quinolin-4(5H)-ones and ethyl bromoacetate. The products were isolated at high yield and characterized by instrumental methods (IR, 1H-, 13C-, and 15N- NMR, MS-ESI, HR-MS, EA). In order to clarify the places of substitution and the structure of the derivatives obtained, molecular modeling of substrates and products was performed. Consideration of the possible tautomeric structures of the substrates confirmed the existence only the most stable keto form. Based on the free energy of monosubstituted ester derivatives, the most stable form were derivatives substituted at sulfur atom of enolic form the used imidazoquinolones. Enolic form referred only to nitrogen atom no 1. The modeling results were consistent with the experimental data. The HOMO electron densities at selected atoms of each substrate has shown that the most reactive atom is sulfur atom. It explained the formation of monoderivatives substituted at sulfur atom. The diester derivatives of the used imidazoquinolones had second substituent at nitrogen atom no. 3. The new diesters can be used as raw material for synthesis of thermally stable polymers, and they can also have biological activity. © 2020 by the authors. Licensee MDPI, Basel, Switzerland.TBU in Zlin [IGA/FT/2019/10]; Interdisciplinary Centre for Mathematical and Computational Modelling in Warsaw, Poland [G49-12

Reaction of 1-substituted 3-(2-hydroxyethylamino)quinoline-2,4(1H,3H)-diones with isothiocyanic acid

3-Chloroquinoline-2,4-diones react with ethanolamine to form 3-(3-hydroxyethylamino)quinoline-2,4-diones. These compounds afford, depending on substituents in positions 1 and 3, four different products from their reaction with isothiocyanic acid: 3-(2-hydroxyethyl)-2-thioxo-3,3a-dihydro-1H-imidazo[4,5-c]quinolin-4(5H)-ones, 9b-hydroxy-3-(2-hydroxyethyl)-2-thioxo-3,3a,5,9b-tetrahydro-1Himidazo[4,5-c]quinolin-4(2H)-ones, 3-(2-hydroxyethyl)-2-thioxo-2,3-dihydro-1H-imidazo[4,5-c]quinolin-4(5H)-ones, or 1 '-methyl-7a-phenyl-5-thioxo-3,5,6,7a-tetrahydro-2H-spiro[imidazo[5,1-b]oxazole-7,3 '-indolin]-2 '-one.TBU in Zlin [IGA/FT/2019/010

Esters with imidazo [1,5-c] quinazoline-3,5-dione ring spectral characterization and quantum-mechanical modeling

1-phenyl-2H,6H-imidazo[1,5-c]quinazoline-3,5-dione reacts with ethyl bromoacetate under mild conditions to give 2-(ethoxycarbonylmethyl)-1-phenyl-6H-imidazo[1,5-c]quinazoline-3,5-dione (MEPIQ) and next 2,6-bis(ethoxycarbonylmethyl)-1-phenylimidazo[1,5-c]quinazoline-3,5-dione (BEPIQ). The products were isolated at high yield and identified on the basis of IR, 1H- and 13C-NMR, UV spectroscopy, and X-ray crystallography. Diester (BEPIQ) can be presented by 16 possible pair of enantiomers. Only one pair of them is the most stable and crystallizes which is shown crystallographic research. Based on quantum-mechanical modeling, with the use of DFT method, which conformers of mono- and diester and why they were formed was explained. It was calculated that 99.93% of the monoester (MEPIQ) is formed at position No. 2 and one pair of the monoester conformers, from six possible, has the largest share (51.63%). These results afforded to limit the number of diester conformers to eight. Unfortunately, the quantum-mechanical calculations performed that their shares are similar. Further quantum-mechanical modeling showed that conformers are able to undergo mutual transformations. As a result only one pair of diester conformers forms crystals. These conformers have substituents in trans position and these substituents are located parallel to imidazoquinazoline ring. This allows for the denser packing of the molecules in the unit cell. © 2017, The Author(s).IGA/FT/2016/004, UTB, Univerzita Tomáše Bati ve ZlíněInterdisciplinary Centre for Mathematical and Computational Modelling in Warsaw [G49-12]; TBU in Zlin [IGA/FT/20017/005

Reaction of tertiary 2-chloroketones with cyanide ions: Application to 3-chloroquinolinediones

3-Chloroquinoline-2,4-diones react with cyanide ions in dimethyl formamide to give 3-cyanoquinoline-2,4-diones in small yields due to the strong hindrance of the substituent at the C-3 atom. Good yields can be achieved if the substituent at this position is the methyl group. In the methanol solution, the reaction proceeds by an addition mechanism to form 2-oxo-1a,2,3,7b-tetrahydrooxireno[2,3-c]quinoline-7b-carbonitriles, from which 4-hydroxy-3-methoxy-2-oxo-1,2,3,4-tetrahydroquinoline-4-carbonitriles are subsequently formed by opening of the epoxide ring with methanol. Some minor products of these reactions have also been isolated. The 1 H, 13 C and 15 N NMR spectra of the prepared compounds were measured, and all resonances were assigned using appropriate two-dimensional spectra. © 2021 The Authors. Published by Wiley-VCH GmbH.Tomas Bata University in Zlin [IGA/FT/2020/007] Funding Source: MedlineUniverzita Tomáše Bati ve Zlíně: IGA/FT/2020/00

Unprecedented reaction course of 1-phenyl-2H,6H-imidazo[1,5-c]quinazoline-3,5-dione with 3-M excess of ethylene oxide

The reaction of 1-phenyl-2H,6H-imidazo[1,5-c]quinazolino-3,5-dione (4) with 3-molar excess ethylene oxide was described. The resulting product was characterized by spectroscopic techniques ( 1 H-, 13 C-NMR, IR, and UV) and by X-ray crystallography. It was expected to produce a product of the subsequent reaction in the hydroxyl groups of the initially formed diol—1-phenyl-2,6-bis(2-hydroxyethyl)imidazo[1,5-c]quinazoline-3,5-dione (7) with ethylene oxide (5). However, crystallographic studies revealed that the proper and only product of the reaction is 3-{2-[1,3-bis(2-hydroxyethyl)-2-oxo-4-phenylimidazolidin-5-yl]phenyl}-1,3-oxazolidin-2-one (8). This product was formed by quinazoline ring opening which occurred in the presence of more than 2-molar excess ethylene oxide. In the work, the exemplary reaction mechanism explaining the formation of the unexpected product was proposed. In order to understand the reasons of quinazoline ring opening, the quantum mechanical modeling was performed. Energy of transition states indicated that the reaction with the third mole of ethylene oxide was controlled by kinetics. © 2019, The Author(s).Interdisciplinary Centre for Mathematical and Computational Modelling in Warsaw [G49-12]; European Union from the European Regional Development Fund under the Operational Programme Innovative Economy, 2007-2013; DS budget; internal grant of TBU in Zlin [IGA/FT/2017/005

Rearrangements of 1-substituted 9b-hydroxy-3,3a,5,9b-tetrahydro-1H-imidazo[4,5-c]quinoline-2,4-diones. An unexpected pathway to new indole and imidazolinone derivatives

Jsou popsány mechanismy molekulárních přesmyků titulních látek na indolové a imidazolinonové derivátyMechanisms of the molecular rearrangements of title compounds to indole and imidazolinobne derivatives are described

Molecular rearrangement of 1-substituted 9b-hydroxy-3,3a,5,9b-tetrahydro-1H-imidazo[4,5-c]quinoline-2,4-diones - an unexpected pathway to new indole and imidazolinone derivatives

Nové deriváty indolu a imidazolidinu byly připraveny molekulárním přesmykem titulních látek ve vroucí kyselině octovéNew derivatives of indole and imidazolidine were prepared by molecular rearrangement of title compounds in boiling acetic aci

Rearrangements of imidazo[4,5-c]quinoline-2,4-dionů

Byl studován reakční mechanismus molekulárního přesmyku imidazochinolindionů. Je diskutován vliv substituce ve výchozí látce na typ produktu přesmyku.The reaction mechanism of the molecular rearrangement of imidazoquinolinediones was studied. The influence of the character of the substitution in initial compounds on the type of rearranged product is discussed

Molecular rearrangement of 9b-hydroxy-imidazo[4,5-c]quinoline-2,4-diones - an easy pathway to spiroindolinones

9b-Hydroxyimidazo[4,5-c]chinolin-2,4-diony se přesmykují v kyselém prostředí za vzniku tří odlišných spiroindolinonů v závislosti na typu substituce v poloze 3a.9b-Hydroxyimidazo[4,5-c]quinoline-2,4-diones rearrange in an acidic medium to give three different spiroindolinones depending on the type of substitution in position 3a