A convenient synthesis method of 5-oxopyrazolo[4,3-b]pyridine-6-carboxylic acids and their nitriles
作者:Georgiy G. Yakovenko、Oleh А. Lukianov、Andriy V. Bol’but、Mikhailo V. Vovk
DOI:10.1007/s10593-019-02603-5
日期:2019.12
N-Boc-protected 5-formyl-1H-pyrazol-4-amines react with malonic acid in pyridine in the presence of pyrrolidine at 45–50°С or with malonic acid monomethyl ether in the presence of pyrrolidine in AcOH under reflux with the formation of 5-oxo-4,5-dihydro-1Hpyrazolo[4,3-b]pyridine-6-carboxylic acids. The reaction of N-Boc-protected 5-formyl-1H-pyrazol-4-amines with cyanoacetic acid in pyridine in the
N -Boc保护的5-甲酰基-1 H-吡唑-4-胺在吡咯烷存在下于45–50°C下与吡啶中的丙二酸反应,或在AcOH中在吡咯烷存在下与丙二酸单甲醚在回流下与乙酸反应5-氧代-4,5-二氢-1 H吡唑并[4,3 - b ]吡啶-6-羧酸的形成。的反应Ñ -Boc保护的5-甲酰基-1- ħ在45-50℃С引线-吡唑-4-胺与在吡咯烷的存在下的吡啶氰基乙酸到5-氧代-4,5-二氢形成-1 H-吡唑并[4,3 - b ]吡啶-6-腈。后者也可以通过N的环缩合获得在氰基乙酸甲酯的存在下,在吡咯烷存在下,在回流下于AcOH中或在含有吡咯烷的MeCN和催化量的脯氨酸中加热回流-Boc保护的5-甲酰基-1 H-吡唑-4-胺与氰基乙酸甲酯。