Acetic Anhydride → 2-(4-Fluorophenyl)-3-acetylpyrazolo[1,5-a]pyridine

Participants

Reaction Steps

A mixture of 2-(4-fluorophenyl)pyrazolo[1,5-a]pyridine (2.00 g, 9.42 mmol) in acetic anhydride (20 mL) and conc. H2SO4 (2 drops) was stirred and heated at reflux for 30 min. The mixture was cooled to room temperature, poured into ice water (300 mL), and basified (pH=10) using 1N NaOH(aq). The resulting orange precipitate was collected by filtration, washed with water, air-dried, then dried under high-vacuum to afford the title compound as an orange solid, 2.60 g (quant.). 1H NMR (CDCl3) δ 8.56 (d, 1H, J=6.9 Hz), 8.45 (d, 1H, J=9.3 Hz), 7.62 (m, 2H), 7.54 (m, 1H), 7.24 (m, 2H), 7.08 (m, 1H), 2.20 (s, 3H): MS (+ve ion electrospray) 255 (100), (MH+).

Provenance & Evidence