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16th April 2019 @ 15:52
Reagent Mass/g Moles/mmol Equivalents
diacetoxyiodobenzene  0.023 0.0714 0.9
2-chloro-6-(2-hydrazinyl(4-carboxybenzylidene))pyrazine 0.022 0.0795 1.0

Yield: 40%

Procedure

PIDA (0.023 g, 0.0714 mmol, 0.9 eq.) was added to a stirred solution of the intermediate pyrazine I1 (0.022 g, 0.0795 mmol, 1 eq.) and DCM (10 mL, 0.157 mol, 2 eq.) at rt under N. The resulting mixture was stirred at rt for 150 min. Then, the solvent was evaporated under reduced pressure to give the crude product. Purification by flash column chromatography on silica with 80:19:1 EtOAc-PET ether-Acetic acid as eluent gave P1 (0.0087 g, 40%) as a light yellow powder

Analytical Data 

mp 269 – 274 °C; RF (80:19:1 EtOAc-PET ether-Acetic acid) 0.26; 1H NMR (300 MHz, CDCl3) 𝛿# 9.31 (s, 1H), 8.19-8.16 (d, J = 9.0 Hz, 2H), 7.85 (s, 1H), 7.71-7.68 (d, J = 9.0 Hz, 2H), 3.42 (s, 1H); MS (ESI) m/z calculated for C12H8ClN4O2 (M + H)+ 275.0329, found 275.0330 (0.4 ppm error)

1H NMR spectrum (300 MHz) of 5-chloro-3-(4-carboxyphenyl)-[1,2,4]triazolo[4,3- a]pyrazine P1in CDCl3.

ESI Mass spectrum of 5-chloro-3-(4-carboxyphenyl)-[1,2,4]triazolo[4,3-a]pyrazine P1.

Risk Assessment 

Risk Assessment

Reaction Scheme

Reaction Scheme
Attached Files
Risk Assessment
1H NMR spectrum (300 MHz) of 5-chloro-3-(4-carboxyphenyl)-[1,2,4]triazolo[4,3- a]pyrazine P1in CDCl3.
ESI Mass spectrum of 5-chloro-3-(4-carboxyphenyl)-[1,2,4]triazolo[4,3-a]pyrazine P1.
Reaction Scheme