2-Acetoxy-6-phenylpyrazine

Phenylpyrazine 4-oxide (268) gave a separable mixture of 2-acetoxy-6-phenylpyrazine (269), 2-acetoxy-3-phenylpyrazine (270), and 2-acetoxy-5-phenylpyrazine (271) [Ac20, Et3N, reflux, A, 6 h 68, 11, 8% respectively (by NMR), isolated in much lower yields].1575... 

Acetamido-3-acetoxy methy lpy razi ne 2-Acetamido-6-azidopyrazine 2-Acetamido-5-benzylamino-3-guanidinocarbonylpyrazine 2-Acetamido-3-benzyl-5-phenylpyrazine... 

When 2-hydroxy-3,5-diphenylpyrazine 1-oxide was heated under reflux with an excess of acetic anhydride, a crystalline triacetoxy compound was obtained which was thought to have an open chain structure [AcO-CH=CPh-N=CPh-C(OAc)=N-OAc], but when the 2-hydroxypyrazine-l-oxide was boiled with a mixture of acetic anhydride and acetic acid, 2,6-diacetoxy-3,5-diphenylpyrazine was obtained (873) which was hydrolyzed by potassium hydrogen carbonate in methanol to 2,6-dihydroxy-3,5-diphenylpyrazine (873). 2-Hydroxy-5-methyl-3-phenylpyrazine 1-oxide behaved differently and when refluxed with acetic anhydride gave 5-acetoxymethyl-2-hydroxy-3-phenylpyrazine (100) and 2-hydroxy-3-methyl-5-phenylpyrazine 1-oxide similarly gave 3-acetoxymethyl-2-hydroxy-5-phenylpyrazine (873). When 2- l-hydroxy-2 -methylpropyl)-5-isobutylpyrazine 1-oxide was heated with a mixture of acetic anhydride and sodium acetate on a water bath 2-(l -acetoxy-2 -methylpropyl)-5-isobutylpyrazine 1 oxide was obtained (760a). 

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