Methylpyrazolo[1,5-a]pyrazine-4-carboxylates were synthesized by palladium-catalyzed carbonylation of 4-chloropyrazolo[1,5-a]-pyrazines at elevated pressure and converted via nitrile intermediates to the corresponding amidoximes and amidines. Cyclocondensation of the obtained amidoximes with trifluoroacetic anhydride or ethyl chloroformate and amidines with acetoacetate or ethyl ethoxymethylidenemalonate were used to synthesize new 4-(1,2,4-oxadiazolyl)- and 4-(pyrimidin-2-yl)-substituted pyrazolo[1,5-a]pyrazines.

中文翻译：

---

吡唑并[1,5-a]吡嗪-4-羧酸酯的4-杂基取代衍生物的合成

通过在高压下钯催化4-氯吡唑并[1,5- a ]-吡嗪的羰基合成甲基吡唑并[1,5 - a ]吡嗪-4-羧酸酯，然后通过腈中间体将其转化为相应的a胺肟和am。所得酰胺肟与三氟乙酸酐或氯甲酸乙酯的环缩合，am与乙酰乙酸酯或乙氧基甲基亚甲基丙二酸的乙酯的环缩合反应可合成新的4-（1,2,4-恶二唑基）-和4-（嘧啶-2-基）取代的吡唑并[1]。 ，5- a ]吡嗪。