论文信息 - A Concise Synthesis of a Tetrahydropyrazolopyrazine Building Block

A Concise Synthesis of a Tetrahydropyrazolopyrazine Building Block

A concise synthesis of a tetrahydropyrazolopyrazine building block is described. 5-Methyl-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrazin-2-ylamine was prepared in three steps and 80% yield from 5-nitro-2H-pyrazole-3-carboxylic acid. This compound was then coupled with 4-bromo-6-chloro-2-methyl-2H-pyridazin-3-one in the presence of sodium tert-pentoxide to give the target product in 87% yield. The process was successfully scaled up to a multihundred gram scale.

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