Dorzolamide → Dorzolamide tartrate

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Dorzolamide trans racemate of formula (II) (0.8 g) and (−)-di-p-toluoyl-L-tartaric acid (0.22 g) were dissolved in refluxing 2-propanol (45 mL). The so obtained solution was distilled at normal pressure up to a final volume of 20 mL. The resulting suspension was stirred at refluxing temperature further 2 hours and then cooled to 20° C. over 7 hours. The solid was isolated by vacuum filtration washing with 2-propanol (4 mL) and then dried in vacuum oven at 40° C. to give Dorzolamide tartrate (1st crop) (0.626 g). This compound (0.601 g) was dissolved in refluxing 2-propanol and the solution was distilled at normal pressure up to a final volume of 18 mL. The resulting suspension was cooled to 20° C. over 7 hours. The solid was isolated by vacuum filtration washing with 2-propanol (4 mL) and then dried in vacuum oven at 40° C. to give Dorzolamide tartrate (2nd crop) (0.49 g). This compound was submitted to a further re-crystallization following the latter procedure (the solution was distilled at normal pressure up to a final volume of 15 mL). The resulting solid was isolated by vacuum filtration then dried in vacuum oven at 50° C. to give the title compound (0.379 g; 85-87% e.e.) as a white solid.

Herkunft & Nachweise