1-烷基-N -Boc -5-甲酰基吡唑-4-胺与丙二腈和氰基乙酰胺反应,分别形成5-氨基-1 H-吡唑并[4,3- b ]吡啶腈和酰胺。所得衍生物与氯乙醛,溴三氟丙酮或溴丙酮酸乙酯的环缩合导致咪唑并[1,2- a ]吡唑并[3,4- e ]吡啶或吡唑并[3',4',5,6]吡啶[2,3- d ]嘧啶衍生物与原酸酯,乙基草酰氯或羰基二咪唑的环缩合反应。
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。
A Beckmann rearrangement initiated by trifluoromethanesulfonic anhydride in the synthesis of compounds containing a new pyrazolo[3',4':5,6]pyrido[3,2-b]azepine heterocyclic system
作者:Georgiy G. Yakovenko、Marta S. Yagodkina-Yakovenko、Sergey Yu. Suykov、Mikhailo V. Vovk
DOI:10.1007/s10593-021-02893-8
日期:2021.2
N-Boc-5-formylpyrazol-4-amines reacted with 1,3-cyclohexanediones in AcOH–1,4-dioxane medium in the presence of pyrrolidine, resulting in the formation of pyrazolo[4,3-b]quinolin-8-one derivatives that were converted into the respective oximes. A reaction of the latter with trifluoromethanesulfonic anhydride under mild conditions was used to synthesize hexahydropyrazolo[3',4':5,6]pyrido[3,2-b]-azepin-4-ium
在吡咯烷存在下,N -Boc-5-甲酰基吡唑-4-胺与1,3-环己二酮在AcOH-1,4-二恶烷介质中反应,从而形成吡唑并[4,3 - b ]喹啉-8-一种被转化为相应肟的衍生物。在温和的条件下,后者与三氟甲磺酸酐的反应被用于合成六氢吡唑并[3',4':5,6]吡啶并[3,2 - b ] -ze庚因-4-三氟甲磺酸鎓盐。
Synthesis of methyl(ethyl) pyrazolo[4,3-b]pyridine-6-carboxylates and their conversion to tert-butyl 4,5,6,7-tetrahydropyrazolo-[4,3-b]pyridine-6-carboxylates
作者:Georgiy G. Yakovenko、Lesya N. Saliyeva、Eduard B. Rusanov、Il’ya S. Donchak、Mykhailo V. Vovk
DOI:10.1007/s10593-021-03032-z
日期:2021.11
N-Boc-4-aminopyrazole-5-carbaldehydes react with methyl 3,3-dimethoxypropanoate or β-keto esters in acetic acid under reflux to form methyl(ethyl) pyrazolo[4,3-b]pyridine-6-carboxylates, which were converted to the corresponding tert-butyl carboxylates via intermediate carboxylic acids. Their subsequent hydrogenation on a 10% Pd/C catalyst at 100°C and 25 atm afforded tert-butyl 4,5,6,7-tetrahydropyrazolo[4