Midazolam → Midazolam Maleate

Participants

Reaction Conditions

Reaction Steps

2 g of the crystallized midazolam base, containing 0.039% of compound VIII and 0.464% of compound IX (according to HPLC), was dissolved in a mixture of 0.4 ml of water and 6.0 ml of THF and heated with stirring to 50° C. A solution of maleic acid in 4 ml of THF was added to the reaction mixture and the mixture was stirred for 30 minutes. After cooling to room temperature and agitating for 2 hours the thus formed solid was filtered, washed with 2×5 ml of cold THF and dried under reduced pressure at 50° C. to afford midazolam maleate in 85.6% yield having purity of 99.87%, containing 0.033% of compound VIII and 0.072% of compound IX (according to HPLC).

Provenance & Evidence