Synthesis and anti-inflammatory activity of 2-methoxy-4-(1-phenyl-3-methyl-1H-pyrazol-5-yl)phenol) and its aminomethyl derivatives

Using heat-induced protein denaturation technique, a series of novel synthesized 1,5-diarylpyrazole compounds, namely 2-methoxy-4-(1-phenyl-3-methyl-1H-pyrazol-5-yl)phenol (1) and its aminomethyl derivatives (2a-e) were evaluated for their anti-inflammatory potentiality. The structures of the synthesized compounds were elucidated using FTIR, NMR (¹H & ¹³C) and mass spectral data. The study found that the activity of aminomethyl derivatives (2a-e) was higher than that of parent compound 1. In this series, aminomethyl derivatives bearing dimethylamino-methyl, diethylaminomethyl and pyrrolidinomethyl moieties (2a, 2c and 2e, respectively) were more active than diclofenac sodium, which was used as a standard. A study on the structure-activity relationship (SAR) suggested that the activity of aminomethyl moiety of the compound was influenced by its pKa value. Thus, novel compounds act as potential anti-inflammatory agents.