Synthesis of C-nucleosides. 17. s-Triazolo[4,3-a]pyrazines

Tam, Huynh Dinh; Sarfati, R.; Gouyette, Catherine; Igolen, J.; Bisagni, Émile; Lhoste, Jean‐Marc; Civier, A.

doi:10.1021/jo01321a002

Cited by 29 publications

(7 citation statements)

References 10 publications

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“…2,3-Dichloropyrazine were purchased from Aldrich Chemical Co.. 3-Chloro-2-hydrazinopyrazine, 8-chlorotetrazolo[1,5- a ]pyrazine 12bT (mp 107–107 °C), and 5,8-dimethyltetrazolo[1,5- a ]pyrazine 12cT were synthesized according to the literature. POCl 3 was distilled under vacuum before use.…”

Section: Methodsmentioning

confidence: 99%

Nitrile Ylides: Allenic and Propargylic Structures from Pyrazinylnitrenes. Experimental and Theoretical Characterization

et al. 2014

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Matrix photolysis of 2-pyrazinyl azides/tetrazolo[1,5-a]pyrazines generates nitrile ylides 15 via pyrazinylnitrenes 13 and triazacycloheptatetraenes 14. The nitrile ylides 15 are characterized by IR spectroscopy in conjunction with harmonic and anharmonic vibrational frequency calculations. The nitrile ylides exist in the matrices in the Z,Z-conformations in which they are born. Substitution on the nitrile carbon of nitrile ylides has a profound effect on their structure. Even different conformers of the same molecule can have differences up to 200 cm(-1) in the IR absorptions of the ylide moieties. Nitrile ylides 15a and 15b (R = H or Cl, R' = H) have allenic structures (15 Allenic). Nitrile ylide 15c (R = R' = CH3) has a distinctly propargylic structure (15 Propargylic) in the experimentally observed Z,Z-conformation.

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Section: Methodsmentioning

confidence: 99%

Nitrile Ylides: Allenic and Propargylic Structures from Pyrazinylnitrenes. Experimental and Theoretical Characterization

et al. 2014

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“…3-Ethyl-8-chloro-triazolo[4,3-a]pyrazine (12b). To 3-chloro-2-hydrazinopyrazine (11) (3.0 g, 20.75 mmol), prepared from 2,3-dichloropyrazine and hydrazine using a procedure analogous to that described in the literature, 16 was added 8 mL of triethyl orthopropionate. After refluxing for 10 h, the reaction was cooled to room temperature and the precipitate was filtered.…”

Section: -Chlorotriazolo[43-a]pyrazine (12a)mentioning

confidence: 99%

“…16 The hydrazine intermediate 11 was then cyclized to give the fused ring system 12 using an ortho ester. 16 In a second approach, hydrazinopyrazine 15, prepared from chloropyrazine (14), 17 was acylated with trifluoroacetic anhydride to give 16, which was then condensed in polyphosphoric acid (PPA) to give triazolopyrazine 17. Alternatively, hydrazine intermediate 15 was directly condensed with carboxylic acid in PPA at elevated temperature to give the desired heterocycles 19.…”

Section: Introductionmentioning

confidence: 99%

(2R)-4-Oxo-4-[3-(Trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

et al. 2004

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A novel series of beta-amino amides incorporating fused heterocycles, i.e., triazolopiperazines, were synthesized and evaluated as inhibitors of dipeptidyl peptidase IV (DPP-IV) for the treatment of type 2 diabetes. (2R)-4-Oxo-4-[3-(trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin-7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine (1) is a potent, orally active DPP-IV inhibitor (IC(50) = 18 nM) with excellent selectivity over other proline-selective peptidases, oral bioavailability in preclinical species, and in vivo efficacy in animal models. MK-0431, the phosphate salt of compound 1, was selected for development as a potential new treatment for type 2 diabetes.

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“…Condensation of 2-hydrazinopyrazines with orthoesters gave initially the hydrazonates 235, which cyclize to give the respective derivatives of the title ring system 236 [119,[139][140][141].…”

Section: 24-triazolo[43-a]pyrazinesmentioning

confidence: 99%

The Chemistry of Hydrazonates

Shawali¹,

Sherif

2007

COC

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The chemistry of esters of hydrazonoic acids has gained increased interest in both synthetic organic chemistry and biological fields. Since a large number of developments in the use of such esters, a review of such developments, covering the literature up to mid 2005, seems to be of considerable value. The present review presents their structural features, nomenclature, synthetic methods and chemical reactions. The utility of the latter reactions for synthesis of various heterocyclic ring systems including mono-, bi-, tri-, tetra-, and penta-heterocycles. In addition, their silicon chelates and biological applications are presented.

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Synthesis of C-nucleosides. 17. s-Triazolo[4,3-a]pyrazines

Cited by 29 publications

References 10 publications

Nitrile Ylides: Allenic and Propargylic Structures from Pyrazinylnitrenes. Experimental and Theoretical Characterization

Nitrile Ylides: Allenic and Propargylic Structures from Pyrazinylnitrenes. Experimental and Theoretical Characterization

(2R)-4-Oxo-4-[3-(Trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl]-1-(2,4,5-trifluorophenyl)butan-2-amine: A Potent, Orally Active Dipeptidyl Peptidase IV Inhibitor for the Treatment of Type 2 Diabetes

The Chemistry of Hydrazonates

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