SYNTHESIS OF SUBSTITUTED PYRAZOLO[3,4-<i>d</i>]PYRIMIDINES BY REACTIONS OF 5-AMINO-1-PHENYL-1<i>Н</i>-PYRAZOLE DERIVATIVES WITH <i>N</i>-SUBSTITUTED ISATINS

Abstract

The reaction of N-substituted isatins with 5-amino-1-phenyl-1Н-pyrazole-4-carboxamide in refluxing methanol in the presence of excess sodium methoxide led to cyclocondensation with the formation of 1-R-1'-phenyl-1',7'-dihydrospiro[indole-3,6'-pyrazolo[3,4-d]pyrimidine]-2,4'(1H,5'H)-diones. Analogous reaction with 5-amino-1-phenyl-1Н-pyrazole-4-carbonitrile was a cascade process that involved the formation of 1-R-4'-(methoxy)-1'-phenyl-1',7'-dihydrospiro[indole-3,6'-pyrazolo[3,4-d]pyrimidine]-2(1H)-ones as intermediates and led to N-R-2-[4-(methoxy)-1-phenyl-1H-pyrazolo[3,4-d]pyrimidin-6-yl]anilines.

Authors: Yevgeniya A. Kosheleva, Svetlana M. Medvedeva, Khidmet S. Shikhaliev*, Fedor I. Zubkov, Elena A. Ryzhkova, Mikhail A. Prezent