Sulfamic Acid (H₂NSO₃H): A Low-Cost, Mild, and Efficient Catalyst for the Synthesis of Substituted N-Phenylpyrazoles Under Solvent-Free Conditions

Abstract

N-Phenylpyrazoles are synthesized by condensing phenylhydrazine and 1,3-diketones in the presence of a catalytic amount of sulfamic acid, a mild and an efficient solid acid catalyst, under solvent-free conditions. This condensation proceeds smoothly in shorter reaction time.

GRAPHICAL ABSTRACT

Keywords:

• N-Phenylpyrazoles
• solid acid catalysis
• sulfamic acid

ACKNOWLEDGMENT

M. S. is thankful to the University Grants Commission (UGC), New Delhi, for a fellowship under UGC-SAP.

Notes

Note. Reaction conditions: phenylhydrazine (10 mmol, 0.108 g), pentane-2,5-dione (10 mmol, 0.100 g), catalyst (10 wt% of phenylhydrazine), room temperature (32 °C).

Note. Reaction conditions: phenylhydrazine (10 mmol, 0.108 g), pentane-2,5-dione 10 mmol, 0.100 g), time 5 min, room temperature (32 °C).

Note. Reaction conditions: phenylhydrazine (10 mmol, 0.108 g), pentane-2,5-dione (10 mmol, 0.100 g), sulfamic acid (10wt% of the phenylhydrazine), room temperature (32 °C).