Synthèse de l'oxadiazole‐1,2,4

Moussebois, C.; Lenaers, R.; Eloy, F.

doi:10.1002/hlca.19620450204

Cited by 15 publications

(10 citation statements)

References 3 publications

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“…NOG (4) decomposed at 290 8C (peak), higher than NQ by 44 8C, [12] whereas unsubstituted 1,2,4-oxadiazole became unstable at 87 8C. [17] The DSC profile of NOA (6, m.p. 154 8C, T decomp 265 8C) exhibited much higher thermal stability than ANF (m.p.…”

Section: Zhanda Fumentioning

confidence: 99%

Synthesis and Characterization of Energetic 3‐Nitro‐1,2,4‐oxadiazoles

Fu¹,

Su²,

Wang³

et al. 2012

Chemistry A European J

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Section: Zhanda Fumentioning

confidence: 99%

Synthesis and Characterization of Energetic 3‐Nitro‐1,2,4‐oxadiazoles

Fu¹,

Su²,

Wang³

et al. 2012

Chemistry A European J

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“…± The 1,2,4-oxadiazole ring [1] [2] is a representative of the family of five-membered aromatic heterocycles featuring one O-and two N-atoms. The first 1,2,4-oxadiazoles were described as in early as in the 1880s [3], although the preparation of the unsubstituted parent compound was not reported in the literature until 1962 [4]. 1,2,4-Oxadiazoles exhibit a wide range of biological activity as selective antagonists at the histamine H 3 receptor [5], as potent muscarinic agonists [6], as inhibitors of tyrosine kinases [7], etc.…”

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confidence: 99%

“…± Protonation Pattern. The 1,2,4-oxadiazole ring features three potential protonation sites: the O-atom and two pyridine-like N-atoms, N(2) and N (4). Protonation at the O-atom is unfavorable because of the low stability of the resulting OH cation [15 ± 17] and will not be considered further.…”

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confidence: 99%

Basicity of Phenyl‐ and Methyl‐Substituted 1,2,4‐Oxadiazoles

Trifonov

Volovodenko

Vergizov

et al. 2005

Helvetica Chimica Acta

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Dedicated to Professor Rolf Huisgen on the occasion of his 85th birthdayThe basicity of a series of 3,5-disubstituted 1,2,4-oxadiazoles in aqueous H 2 SO 4 was examined by means of UV and 1 H-NMR spectroscopy. The experimental data were analyzed by the modified Yates ± McClelland method to yield the following pK BH values: 3,5-dimethyl-1,2,4-oxadiazole, À 1.66 AE 0.06; 3-methyl-5-phenyl-1,2,4-oxadiazole, À 2.61 AE 0.02; 3-phenyl-5-methyl-1,2,4-oxadiazole, À 2.95 AE 0.01; 3,5-diphenyl-1,2,4-oxadiazole, À 3.55 AE 0.06. A pK BH value of ca. À 3.7 was estimated for the parent unsubstituted 1,2,4-oxadiazole based on substituents× additivity increments. Possible protonation sites of the compounds were discussed in terms of both experimental data and theoretical calculations (HF/6-31G**). Generally, protonation is most likely to occur at N(4) of the 1,2,4-oxadiazole ring. However, concurrent formation of both N(4)-and N(2)-protonated species in comparable amounts is possible in the case of 3-phenyl-1,2,4-oxadiazoles.

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“…The compound upon acetylation with acetic anhydride afforded the acetoxy derivative 2 (R = COCH3): mp 147-160 °C with cyclization into 3 (R = Me); M+ 194; NMR (CD3SOCD3) 7.68 (dd, H4), 6.52 (dd, H5), 7.93 (dd, H6), 2.14 (s, Me), 6.70 and 6.84 (broad s, NH2 groups) {J4i5 = 8.0, Js,e = 5.0, J4,e = 2.0 Hz).…”

Section: Methodsmentioning

confidence: 99%

“…With methanolic hydroxylamine hydrochloride compound 7 is transformed at room temperature smoothly into 8 (R = Ri = H). On the other hand, the formamidine 7 is hydrolyzed at room temperature to give a mixture of almost equal amounts of compound 1 and 3 (R = H, Ri = CHO) together with a small amount of the pyrazolo [3,[4][5][6]pyridine derivatives (9, R = CHO). The formation of the first two products is easily understood, whereas the formation of the pyrazolo[3,4-6]pyridine system is somewhat surprising.…”

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confidence: 99%