Unknown

Dataset Information

0

One-Flask Synthesis of Pyrazolo[3,4-d]pyrimidines from 5-Aminopyrazoles and Mechanistic Study.


ABSTRACT: A novel one-flask synthetic method was developed in which 5-aminopyrazoles were reacted with N,N-substituted amides in the presence of PBr?. Hexamethyldisilazane was then added to perform heterocyclization to produce the corresponding pyrazolo[3,4-d]pyrimidines in suitable yields. These one-flask reactions thus involved Vilsmeier amidination, imination reactions, and the sequential intermolecular heterocyclization. To study the reaction mechanism, a series of 4-formyl-1,3-diphenyl-1H-pyrazol-5-yl-N,N-disubstituted formamidines, which were conceived as the chemical equivalent of 4-(iminomethyl)-1,3-diphenyl-1H-pyrazol-5-yl-formamidine, were prepared and successfully converted into pyrazolo[3,4-d]pyrimidines. The experiments demonstrated that the reaction intermediates were the chemical equivalents of 4-(iminomethyl)-1,3-diphenyl-1H-pyrazol-5-yl)formamidines. The rate of the reaction could be described as being proportional to the reactivity of amine reactants during intermolecular heterocyclization, especially when hexamethyldisilazane was used.

SUBMITTER: Yen WP 

PROVIDER: S-EPMC6154590 | biostudies-literature | 2017 May

REPOSITORIES: biostudies-literature

altmetric image

Publications

One-Flask Synthesis of Pyrazolo[3,4-d]pyrimidines from 5-Aminopyrazoles and Mechanistic Study.

Yen Wan-Ping WP   Tsai Shuo-En SE   Uramaru Naoto N   Takayama Hiroyuki H   Wong Fung Fuh FF  

Molecules (Basel, Switzerland) 20170516 5


A novel one-flask synthetic method was developed in which 5-aminopyrazoles were reacted with <i>N,N</i>-substituted amides in the presence of PBr₃. Hexamethyldisilazane was then added to perform heterocyclization to produce the corresponding pyrazolo[3,4-<i>d</i>]pyrimidines in suitable yields. These one-flask reactions thus involved Vilsmeier amidination, imination reactions, and the sequential intermolecular heterocyclization. To study the reaction mechanism, a series of 4-formyl-1,3-diphenyl-  ...[more]

Similar Datasets

| S-EPMC4660965 | biostudies-literature
| S-EPMC1470455 | biostudies-literature
| S-EPMC7696985 | biostudies-literature
| S-EPMC6467769 | biostudies-literature
| S-EPMC6257727 | biostudies-literature
| S-EPMC4761914 | biostudies-literature
| S-EPMC2535934 | biostudies-literature
| S-EPMC10999085 | biostudies-literature
| S-EPMC6047171 | biostudies-literature
| S-EPMC3184363 | biostudies-other