反应详情

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).

1. customthe temperature below 25° C
2. aliquotsampled for reaction completion
3. concentrationis concentrated to an oil
4. dissolutionThe resulting oil is dissolved in brine (7.5 volumes)
5. additionPotassium carbonate is added portion wise
6. customthe temperature below 25° C.
7. washThe reaction is then washed with methylene chloride (3×10 volumes)
8. dry with materialthe combined organic layers are dried with sodium sulfate (200 wt %)
9. filtrationThe slurry is then filtered
10. washthe cake washed with methylene chloride (2×3 volumes)
11. waitThe resulting filtrate is held under vacuum for ≧24 hr
12. concentration, to concentrate the title