Oxirenes as Substrates

Such epoxides naturally require a nitrogenous cosynthon to afford pyrazines. Such a rarely used condensation is illustrated by the reaction of octafluoro-2, 

3-epoxybutane [2,3-difluoro-2,3-bis(trifluoromethyl)oxirane 64] with ethylenedi-amine in bis(2-methoxyethyl) ether at 20°C during 90 min to give 2,3-bis(trifluo-romethyl)-l,2,5,6-tetrahydro-2-pyrazinol (65) in 20% yield.936 

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