Water → 1-Methyl-1H-pyrazole-4-sulfonic acid methyl-(2-oxo-ethyl)-amide

Participants

Reaction Steps

Alternatively, 1-methyl-1H-pyrazole-4-sulfonic acid (2,2-dimethoxy-ethyl)-methyl-amide (1.0 equivalents) is suspended in toluene (5 volumes) and water (0.5 volumes) and trifluoroacetic acid is added keeping the temperature below 25° C. The resulting solution is allowed to stir for at least 8 hours below 25° C. and sampled for reaction completion. Once the reaction is deemed complete the solution is concentrated to an oil. The resulting oil is dissolved in brine (7.5 volumes) and water (2.5 volumes). Potassium carbonate is added portion wise to keep the temperature below 25° C. until a pH of 7.5 is achieved. The reaction is then washed with methylene chloride (3×10 volumes) and the combined organic layers are dried with sodium sulfate (200 wt %). The slurry is then filtered and the cake washed with methylene chloride (2×3 volumes). The resulting filtrate is held under vacuum for ≧24 hr., to concentrate the title preparation to a viscous amber oil (92% yield).

Provenance & Evidence