Pyrazolo[1,5-a]pyrazin-4(5H)-ones react regioselectively with N-iodosuccinimide in the presence of N-methylmorpholine to form 7-iodo derivatives. Their carbonylation catalyzed with Pd(dppf)Cl2 under pressure in MeOH solution yielded methyl 4-oxo-4,5-dihydropyrazolo-[1,5-a]pyrazine-7-carboxylates, which were transformed into the corresponding carboxylic acids by alkaline hydrolysis.

中文翻译：

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4-氧代-4,5-二氢吡唑并[1,5-a]-吡嗪-7-羧酸甲酯和相应羧酸的便捷合成

吡唑并[1,5- a ]吡嗪-4(5 H )-酮在N-甲基吗啉存在下与N-碘代琥珀酰亚胺发生区域选择性反应，形成7-碘衍生物。它们在压力下在甲醇溶液中用 Pd(dppf)Cl2 催化羰基化，生成 4-氧代-4,5-二氢吡唑并-[1,5- a ]吡嗪-7-甲酸甲酯，通过碱性水解将其转化为相应的羧酸。