3- Phenylsulfonyl-2-pyrazinecarbonitrile

Phenylthio-2-pyrazinecarbonitrile gave 3 -phenylsulfonyl-2-pyrazinecarboni-trile (49) (ot-C1C6H4C03, CHC13, 10 - 20°C, 3 h 91%) 1507 and 5-bromo-3-methylthio- gave 5-bromo-3-methylsulfonyl-2-pyrazinamine (50) (likewise, 4 days 70%).1012 Also other examples.1551... 

Amination of 2-fluoropyrazine 1-oxide with a variety of amines proceeds smoothly at 40-50°C to form excellent yields of the aminopyrazine A-oxides within 2 h <84H(22)il05>. This reactivity is in contrast to that in the amination of 2-chloropyrazine 1-oxide, where higher temperatures (100-110°C) are needed. An electron-withdrawing cyano substituent adjacent to a phenylsulfonyl group prompts its nucleophilic replacement by amines <92JHC1689>, for example, reaction of 3-phenyl-sulfonylpyrazinecarbonitrile (60) with ethylamine in the presence of triethylamine at room temperature for 2 hours produces 3-(A-ethylamino)pyrazinecarbonitrile (61) in 78% yield (Equation... 

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