# Direct Cyclization/Chlorination Strategy of Hydrazines for Synthesis of 4-Chloropyrazoles by TCCA

## TL;DR

A new method for making 4-chloropyrazoles from hydrazines using TCCA under mild conditions is introduced, achieving high yields.

## Contribution

A novel direct cyclization/chlorination strategy using TCCA for synthesizing 4-chloropyrazoles is proposed.

## Key findings

- The method uses TCCA as both oxidant and chlorinating agent under mild conditions.
- The reaction yields for desired products reached up to 92%.
- The substrate generality was investigated after optimizing reaction conditions.

## Abstract

A new method for synthesis of various 4-chloropyrazoles through the direct cyclization/chlorination of hydrazines by using 1,3,5-trichloroisocyanuric acid (TCCA) as both oxidant and chlorinating agent under mild conditions has been proposed. Based on the detailed optimization of the reaction conditions, the substrate generality has been investigated, and the yields of the desired products are up to 92%.