反应详情

A solution of 2-hydroxy-5-[2-[4-[(2-pyridinylamino)sulfonyl]phenyl]ethenyl]benzoic acid (3 g, 7.5 mmol) in tetrahydrofuran (100 ml) and acetic acid (100 ml) was hydrogenated over palladium on charcoal (10%, 0.3 g) and hydrogen at atmospheric pressure and room temperature for 27 h. The catalyst was filtered off and the solvent was evaporated. The residue was dissolved in a solution of sodium hydroxide (0.3 g) in acetone (30 ml) and water (30 ml). The solution was acidified with hydrochloric acid at ca 50° C. After cooling, the product crystallized yielding 1.6 g (52%).

1. filtrationThe catalyst was filtered off
2. customthe solvent was evaporated
3. dissolutionThe residue was dissolved in a solution of sodium hydroxide (0.3 g) in acetone (30 ml) and water (30 ml)
4. customwas acidified with hydrochloric acid at ca 50° C
5. temperatureAfter cooling
6. customthe product crystallized
7. customyielding 1.6 g (52%)