Direct Preparation of N-Substituted Pyrazoles from Primary Aliphatic or Aromatic Amines

Despite a large number of synthesis procedures for pyrazoles known today, those directly employing primary amines as substrates are rare. Herein, we report an original method for the preparation of N-alkyl and N-aryl pyrazoles from primary aliphatic or aromatic amines as a limiting reagent of the reaction. The protocol utilizes no inorganic reagents and requires a short reaction time, mild conditions, and the use of structurally simple and commercially available starting reagents. During this study, pyrazoles containing a wide variety of N-substituents were obtained using the same procedure for both aliphatic and aromatic amines.

Automated summary

This study presents an original method for the preparation of N-alkyl and N-aryl pyrazoles using primary aliphatic or aromatic amines as a limiting reagent. The protocol avoids the use of inorganic reagents, requires short reaction time, mild conditions, and utilizes commercially available starting reagents. Pyrazoles with a variety of N-substituents were successfully obtained using this method for both aliphatic and aromatic amines.