Synthesis of 5‑Amino‑1<i>H</i>‑pyrazole-4-carbonitriles from <i>N</i>‑Tosylhydrazonesand Its Application in the Preparation of Ibrutinib

A facile method for preparing 5-amino-1<i>H</i>-pyrazole-4-carbonitriles was developed. The reaction exhibited compatibility to various substrates, and different 5-amino-1<i>H</i>-pyrazole-4-carbonitriles were prepared efficiently. Ibrutinib was prepared under palladium-free conditions in six steps in 32.7% overall yield.