Method for preparing medical intermediate 1H - pyrazolo [3, 4 - d] pyrimidine -4 (5H) - ketone
The invention relates to the field of pharmaceutical chemicals, and particularly discloses a preparation of a medical intermediate 1. H- Pyrazolo [3, 4 -]d] Pyrimidin -4 (5)HTo the method for - ketone, aromatic aldehyde and 5 - amino -4 -cyanopyrazole der
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Paragraph 0051-0059
(2021/11/03)
Versatile synthesis of 6-alkyl/aryl-1H-pyrazolopyrimidin-4-ones
Condensation of 5-amino-1H-pyrazole-4-carboxamide (1a) with various aromatic aldehydes furnishes 6-substituted-1H-pyrazolepyrimidin-4(5H)-ones (4a-f) via the intermediates 5-(N-arylideneamino)pyrazole-4-carboxamides (3a-f).Compounds 4a-f have also
Reddy, K Hemender,Reddy, A Panduranga,Veeranagaiah, V
p. 163 - 166
(2007/10/02)
STUDIES ON PYRAZOLOPYRIMIDINE DERIVATIVES. XVIII. FACILE PREPARATION OF 1H-PYRAZOLOPYRIMIDIN-4(5H)-ONES
Reaction of 5-amino-1-phenyl-1H-pyrazole-4-carboxamide (4) with the esters (3a-h) in the presence of sodium ethoxide in ethanol gave 1-phenyl-1H-pyrazolopyrimidin-4(5H)-one (1a) and its 6-substituted derivatives (1b-h).Similar treatment of 5-amino-1-methyl-1H-pyrazole-4-carboxamide (5) with 3a-h gave the 1-methyl-1H-pyrazolopyrimidin-4(5H)-ones (2a-h).