Novel fluorinated chromones

Салоутин, В. И.; Skryabina, Z. É.; Bazyl, I. T.; Чупахин, О. Н.

doi:10.1016/s0022-1139(00)80470-4

Cited by 19 publications

(6 citation statements)

References 2 publications

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“…Ethyl pentafluorobenzoylpyruvate (1e), like other b-DCC, 11,12,23,24,67 readily reacts with ethyl orthoformate to form ethyl 3-ethoxymethylidene-2,4-dioxo-4-pentafluorophenylbutyrate (24). The reactions of compound 24 with amines followed by cyclisation of the resulting ethyl 3- The active methylene group in compounds containing a b-dicarbonyl fragment is the reaction site for azocoupling with aryldiazonium salts to form the corresponding arylhydrazones.…”

Section: Preparation and Reactions Of 3-substituted Polyfluorinated 2...mentioning

confidence: 99%

“…A characteristic feature of pentafluorobenzoylpyruvate 1e and its chelate 2e (see Scheme 1) is their conversion into 2-ethoxycarbonylchromone 3a due to their ability to undergo intramolecular cyclisation to form a six-membered ring. 23,24 Under analogous conditions, ethyl pentafluorobenzoylacetate (34) undergoes selfcondensation. The latter reaction is accompanied by the Dieckmann condensation and intramolecular cyclisation of an intermediate product to yield 1-oxo-3-pentafluorophenyl-1Hpyrano[4,3-b]-6,7,8,9-tetrafluorochromone (35).…”

Section: Reactions Of 2-ethoxycarbonyl(carboxy)-5678-tetrafluorochromonementioning

confidence: 99%

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Fluorine-containing 2,4-dioxo acids in the synthesis of heterocyclic compounds

Салоутин¹,

Burgart²,

Чупахин³

1999

Russ. Chem. Rev.

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Section: Preparation and Reactions Of 3-substituted Polyfluorinated 2...mentioning

confidence: 99%

Section: Reactions Of 2-ethoxycarbonyl(carboxy)-5678-tetrafluorochromonementioning

confidence: 99%

Fluorine-containing 2,4-dioxo acids in the synthesis of heterocyclic compounds

Салоутин¹,

Burgart²,

Чупахин³

1999

Russ. Chem. Rev.

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“…Polyfluorobenzoyl malonates are not often obtained in the pure form and are generally used in situ for the synthesis of the correspond ing 3 oxoesters. [9][10][11] No data were found on other trans formations of this type of compounds.…”

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confidence: 99%

Structure of diethyl (polyfluorobenzoyl)malonates and their thermal intramolecular cyclization

et al. 2011

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The reaction of the C ethoxymagnesium derivative of diethyl malonate with polyfluo robenzoyl chlorides affords the corresponding (polyfluorobenzoyl)malonates prone to thermal cyclization into coumarin derivatives. The compounds obtained are inherent in keto-enol tautomerism.Diethyl (polyfluorobenzoyl)malonates are key inter mediates in the synthesis of polyfluorine containing qui nolones 1-4 and benzothiazines 5 exhibiting antiviral, 6 an tibacterial, 7 and antitumor 8 activity. Fluoroquinolones represent a particular group of modern antibiotics, such as ofloxacin, levofloxacin, and others. Polyfluorobenzoyl malonates are not often obtained in the pure form and are generally used in situ for the synthesis of the correspond ing 3 oxoesters. 9-11 No data were found on other trans formations of this type of compounds.The purpose of the present work is to obtain diethyl (polyfluorobenzoyl)malonates and to study their structures and further chemical transformations.The reactions of 2,3,4,5 tetrafluorobenzoyl (1а) and pentafluorobenzoyl (1b) chlorides with malonic ester un der the action of magnesium ethoxide afforded diethyl (polyfluorobenzoyl)malonates (2a,b) (Scheme 1) similarly to earlier works. 11-13The structures of isolated (polyfluorobenzoyl)malon ates 2a,b (Scheme 2) were studied in detail. Their individ ual character was confirmed by TLC, the quantitative composition was established using elemental analysis, and structural features and tautomeric composition were studied by IR spectroscopy and 1 H and 19 F NMR spectroscopy.Compounds 2a,b are prototropic systems and, accord ing to the data of NMR spectroscopy, in CDCl 3 solutions they exist as a mixture of tautomeric forms A and B. The presence of the enol form in the spectra is indicated by the signal of the proton of the hydroxyl group at δ 13.82-13.96, and keto form А can easily be identified by the signal of the methine proton at δ 5.10-5.42. The sig * Dedicated to Academician of the Russian Academy of Scien ces V. N. Charushin on his 60th birthday. Scheme 1 X = H (a), F (b) i. EtOMgCH(CO 2 Et) 2 , toluene, 0°С; ii. 150-200°C. Scheme 2 X = H (a), F (b)

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“…1, 2, 11 ± 23 Pentafluorobenzoylpyruvates are prepared from pentafluoroacetophenone in the presence of lithium hydride. 3,5,24,25 It is convenient to isolate and purify labile AP as their copper(II) chelates 3. 1,13,14,16 This is especially required in the case of pentafluorobenzoylpyruvates, 5,24,25 which cyclise very easily to chromone derivatives due to the presence of ortho-fluorine atoms in the benzoyl substituent.…”

mentioning

confidence: 99%

“…3,5,24,25 It is convenient to isolate and purify labile AP as their copper(II) chelates 3. 1,13,14,16 This is especially required in the case of pentafluorobenzoylpyruvates, 5,24,25 which cyclise very easily to chromone derivatives due to the presence of ortho-fluorine atoms in the benzoyl substituent. Hydrolysis of the esters 2 to the corresponding acids 4 is normally carried out in an acid medium, 1,23,26,27 although examples of alkaline hydrolysis are also documented.…”

mentioning

confidence: 99%