SYNTHESIS OF METHYL(ETHYL) PYRAZOLO[4,3-<i>b</i>]PYRIDINE-6-CARBOXYLATES AND THEIR CONVERSION TO <i>tert</i>-BUTYL 4,5,6,7-TETRAHYDROPYRAZOLO-[4,3-<i>b</i>]PYRIDINE-6-CARBOXYLATES

Authors

  • Георгий Г. Яковенко National University ''Kyiv-Mohyla Academy'', 2 Hrygorija Skovorody St., Kyiv 04655, Ukraine Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanska St., Kyiv 02660, Ukraine
  • Леся Н. Салиева Lesya Ukrainka Eastern European National University, 13 Voli Ave., Lutsk 43025, Ukraine
  • Эдуард Б. Русанов Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanska St., Kyiv 02660, Ukraine
  • Илья С. Дончак Enamine Ltd., 78 Chervonotkatska St., Kyiv 02094, Ukraine
  • Михаил В. Вовк Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 Murmanska St., Kyiv 02660, Ukraine

DOI:

https://doi.org/10.1007/6343

Keywords:

alkyl pyrazolo[4, 3-b]pyridine-6-carboxylates, N-Boc-4-aminopyrazole-5-carbaldehydes, 3, 3-dimethoxypropionate, β-keto esters, tetrahydropyrazolo[4, Pd/C catalytic hydrogenation.

Abstract

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[4,3-b]pyridine-6-carboxylates.

 

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Published

2021-11-26

Issue

Vol. 57 No. 11 (2021)

Section

Original Papers