Nucleophilic substitutions in 6,7-difluoroquinoxalines

Charushin, Valery N.; Mokrushina, G. A.; Ткачев, А. В.

doi:10.1016/s0022-1139(00)00345-6

Cited by 16 publications

(11 citation statements)

References 10 publications

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“…Yield 0.8 g action between the C 2 and 9-F nuclei. Such carbonfluorine couplings between atoms located in different rings have been reported [16].…”

Section: Methodssupporting

confidence: 63%

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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“…Yield 0.8 g action between the C 2 and 9-F nuclei. Such carbonfluorine couplings between atoms located in different rings have been reported [16].…”

Section: Methodssupporting

confidence: 63%

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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“…6,7-Difluoroquinoxalines have been obtained from the corresponding 1,2-diamino-4,5-difluorobenzene and glyoxal, and quaternization of 6,7-difluoroquinoxalines by action of the Meervein reagent has been studied [95]. The reaction of 6,7-difluoroquinoxalines 111 with cycloalkylimines, hydrazine, sodium hydroxide as well as alkoxides was found to be dependent on the nature of nucleophile, thus resulting in the displacement of one or two fluorine atoms (Scheme 34) [96]. Also, the features of nucleophilic substitution of fluorine atoms in 2,3-disubstituted 6,7-difluoroquinoxalines by action of amines, sodium azide, and methoxide have been established [97].…”

Section: Scheme 32 Scheme 33mentioning

confidence: 99%

Fluorinated benzazoles and benzazines

Носова

Mochul’skaya

Kotovskaya

et al. 2006

Heteroatom Chemistry

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“…The JNK signal transduction pathway is implicated in many pathological conditions, including cancer, diabetes and neurodegenerative diseases [18][19], therefore, JSP-1 might be a novel potential therapeutic target for treating diseases associated with dysfunctional JNK signaling. According to the literature 6-aminoquinoxalines could be prepared by condensation of corresponding ortho-phenylenediamines with 1,2-dioxo compounds [20][21] or by nucleophilic substitution of haloquinoxalines [22][23][24][25][26]. Since appropriately substituted ortho-phenylenediamines are not always readily available, the former route is not very useful for the construction of 6-aminoquinoxaline libraries and consequently, the latter one was considered a more attractive option to synthesize the target compounds.…”

Section: Introductionmentioning

confidence: 99%

“…Since appropriately substituted ortho-phenylenediamines are not always readily available, the former route is not very useful for the construction of 6-aminoquinoxaline libraries and consequently, the latter one was considered a more attractive option to synthesize the target compounds. However, the nucleophilic substitution reaction, which affords 26-88% yields of the target compounds after reactions at high temperature for 3-22 hours, usually requires an electron-withdrawing substituent such as a fluorine atom or nitro group at the ortho-position of the 6-halo substituted quinoxalines [22][23][24][25]. There is one report claiming that 2,3-dimethyl-6-chloroquinoxaline or methyl-6-fluoroquinoxaline reacted with methylamine in sealed tube for [16][17][18][19][20][21][22][23][24][25][26] hours to produce the expected product in 63-80% yield [26].…”

Section: Introductionmentioning

confidence: 99%