反应详情

Pemirolast free acid was prepared by dissolving pemirolast potassium in water and acidifying to pH 1 with 6M HCl which caused the free acid to precipitate from solution. The crystals formed were filtered, washed with water and dried under vacuum. Pemirolast potassium was in turn prepared analogously to the methodology described in Example 4 (steps Ia and Ib) below, using 2M KOH instead of 2M NaOH, and recrystallising from water:isopropanol in a 1:2, instead of a 2:1, ratio.

1. customto precipitate from solution
2. customThe crystals formed
3. filtrationwere filtered
4. washwashed with water
5. customdried under vacuum
6. customprepared analogously to the methodology
7. customrecrystallising from water