Abstract Alkylation of pyrazoles with 2-chloroethylamine was performed under conditions of phasetransfer catalysis. Depending on the substrate acidity, the electrophilic substitution process may be accompanied by dehydrochlorination of the alkylating agent, so that 6 equiv of 2-chloroethylamine should be used in the alkylation of 3, 5-dimethylpyrazole.
![N-{2-[3(5)-methyl-1H-pyrazol-1-yl]ethyl}ethane-1,2-diamine Structure](https://image.chemsrc.com/caspic/384/1101099-34-6.png)
![N'-[2-(3,5-dimethylpyrazol-1-yl)ethyl]ethane-1,2-diamine Structure](https://image.chemsrc.com/caspic/171/511513-23-8.png)