Hydrochloric Acid → Cimicoxib

Participants

Reaction Steps

A mixture of N-tert-butyl-4-[4-chloro-5-(3-fluoro-4-methoxyphenyl)imidazol-1-yl]benzenesulfonamide (37.0 g, 85 mmol, obtained in example 4), concentrated HCl (200 mL) and H2O (200 mL) is heated at reflux for 3 h. The mixture is allowed to cool and is brought to pH 6 with 6N NaOH. A white precipitate appears, which is collected by filtration and washed with plenty of H2O and then with CHCl3. 31 g of the title compound of the example is obtained (yield: 97%), which are recrystallized from acetonitrile.

Provenance & Evidence