5(6)‐Fluoro‐6(5)‐R‐benzofuroxans: Synthesis and NMR 1H, 13C and 19F Studies.

Kotovskaya, S. K.; Romanova, Svetlana A.; Charushin, V. N.; Кодесс, М. И.; Чупахин, О. Н.

doi:10.1002/chin.200427120

Cited by 3 publications

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“…Intramolecular cyclization of aroyl derivatives XVIIIa and XVIIIb to 7,8,9-trifluoro-4H- It should be noted that the above spectral data are equally consitent with structure XIX and alternative 4H- [1,2,4]triazolo[4,3-a]quinazolin-5-one structure XXI. To distinguish between these alternative structures, we analyzed the 13 C NMR spectra of XIXa and XIXb (see Experimental).…”

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confidence: 81%

“…1 cyano-7,8,9-trifluoro-4,5-dihydroimidazo[1,2-a N-(1H-1,2,4-Triazol-5-yl)-2,3,4,5-tetrafluorobenzamide (XVIIIa). Tetrafluorobenzoyl chloride (I), 5.2 g (24 mmol), was added to a suspension of 1.6 g (19 mmol) of 5-amino-1,2,4-triazole XVIIa in 20 ml of anhydrous toluene.…”

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confidence: 99%

“…Yield 3.8 g (78%), mp 245-247°C. 1 1 mmol), was added to a suspension of 0.6 g (2.1 mmol) of amide XVIIIa in 15 ml of anhydrous acetonitrile. The mixture was heated for 5 h under reflux and evaporated, the residue was treated with 15 ml of water and 1 ml of acetic acid, and the colorless precipitate was filtered off.…”

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Fluorine-Containing Heterocycles: XII. Fluorine-Containing Quinazolin-4-ones and Azolo[a]quinazolinone Derivatives

Lipunova¹,

Носова²,

Laeva³

et al. 2005

Russ J Org Chem

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Methods for the synthesis of fluorine-containing derivatives of 2-imino-1,3-diphenylquinazolin-4-one, imidazo[1,2-a]quinazolin-5-one, pyrazolo[1,5-a]quinazolin-5-one, and [1,2,4]triazolo[1,5-a]quinazolin-5-one were developed on the basis of the reaction of tetrafluorobenzoyl chloride with N,N'-diphenylguanidine and aminoazoles. * For communication XI, see [1].Fused quinazolin-4-one derivatives attract strong interest from the viewpoint of their potential biological activity. Antibacterial, antitoxoplasmatic, antihypertensive, and antihistaminic agents, phosphodiesterase inhibitors, and compounds possessing other kinds of biological activity have been revealed among quinazolin-4-one derivatives [2][3][4][5][6][7][8]. A known procedure for building up such heterocyclic systems is based on cyclization of 2-halo-substituted benzoyl chlorides with difunctional nitrogen-centered nucleophiles [4,[9][10][11]. This approach was not applied previously to the synthesis of fused imidazo-, pyrazolo[a]-and triazolo[a]-quinazolinones. There are published data only on the preparation of triazolo[a]quinazolinone derivatives via transformations of quinazolinones having a sulfanyl, hydrazino, thiosemicarbazido, or S-methylisothiosemicarbazido group in the 2-position [2,5,[12][13][14][15].In continuation of our studies on the synthesis of fused fluorine-containing nitrogen heterocycles, we have developed a general procedure for the preparation of fluorinated triazolo-, pyrazolo-, and imidazo[a]-quinazolinones by reaction of tetrafluorobenzoyl chloride with difunctional N,N'-dinucleophiles. By acylation of N,N'-diphenylguanidine (II) with tetrafluorobenzoyl chloride (I) in boiling toluene we obtained N, N'-diphenyl-N-(2,3,4,5-tetrafluorobenzoyl)-guanidine (III) (Scheme 1). The 1 H NMR spectrum of III confirmed the presence in its molecule of two

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Fluorine-Containing Heterocycles: XII. Fluorine-Containing Quinazolin-4-ones and Azolo[a]quinazolinone Derivatives

Lipunova¹,

Носова²,

Laeva³

et al. 2005

Russ J Org Chem

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“…Features of tautomerism in the series of furoxanes 8 (R = F, morpholino) have been studied by 1 H, 13 C, and 19 F NMR methods. The factors affecting tautomeric equilibria as well as thermodynamic characteristics of both isomers have been determined (Scheme 4) [17,18].…”

Section: Fluorinated Benzazolesmentioning

confidence: 99%

“…Nucleophilic displacement of a fluorine atom at C-6 in furoxane 8 allows one to modify the benzene ring, while the furoxane ring remains unchanged in this reaction (compounds 10). Electrophilic substitution reactions on fluorinated benzofuroxanes and 8 bearing an electron-donating substituent R are accompanied with the Boulton-Katrizky rearrangement, resulting in the formation of nitro derivatives of benzofurazanes 11 and benzotriazoles 12 (Scheme 5) [18,22].…”

Section: Fluorinated Benzazolesmentioning

confidence: 99%