New xanthine oxidase inhibitors of the pyrazolo[3,4-d]pyrimidine and pyrazolo[3,4-b]pyridine class. II. Comparative evaluation of their effectiveness was written by Vartanyan, L. S.;Rashba, Yu. E.;Kazachenko, A. I.;Korbukh, I. A.;Bulychev, Yu. N.;Preobrazhenskaya, M. N.. And the article was included in Khimiko-Farmatsevticheskii Zhurnal in 1982.Reference of 49834-67-5 The following contents are mentioned in the article:
Thirty pyrazolo[3,4-d]pyrimidines I (R = H, CH2NMe2, N-methylpiperazinylmethyl, or piperidinylmethyl; R1 = H, CH2NEt2, or N-methylpiperazinylmethyl; R2 = H or Me) and II [R = H, CN, CH2CN, C(NH2):NOH, etc.; R1 = SH, SMe, NHNH2, etc.; R2 = H, SH, or SMe] and 5 pyrazolo[3,4-b]pyridines III (R = H or OH; R1 = H, OH, SH, Cl, or SMe) were tested for xanthine oxidase [9002-17-9]-inhibiting activity. The kinetics of xanthine oxidase inhibition by I, II, and III was studied. Structure-activity relations are discussed. This study involved multiple reactions and reactants, such as 1H-Pyrazolo[3,4-b]pyridin-4-ol (cas: 49834-67-5Reference of 49834-67-5).
1H-Pyrazolo[3,4-b]pyridin-4-ol (cas: 49834-67-5) belongs to pyrazole derivatives. An alternative way to synthesize multisubstituted pyrazoles is the Csingle bondH arylation of simple pyrazoles. Protonation of pyrazole in strong acid leads to pyrazolium cations, which undergo electrophilic substitution preferentially at C3 rather than C4. The pyrazole anion is not reactive toward nucleophiles but is mostly reactive to electrophiles.Reference of 49834-67-5
Referemce:
Pyrazole – Wikipedia,
Pyrazoles – an overview | ScienceDirect Topics