Hydrochloric Acid → Bosentan hydrate

Participants

Reaction Steps

To the pure ammonium salt of Bosentan (60 gm), dichloromethane (180 ml) and water (180 ml) were added and the pH of the reaction mixture was adjusted to 5 to 6 using concentrated hydrochloric acid. The reaction mixture was stirred for 30 minutes. The dichloromethane layer was separated and it was washed with water (180 ml). The dichloromethane layer was subjected to evaporation under reduced pressure to obtain syrup. To this syrup, ethanol (120 ml) was added and the mixture was heated to 55° C. to 60° C. to obtain clear solution. Water (120 ml) was slowly added to the clear solution and was stirred for 30 minutes at 55° C. to 60° C. The reaction mixture was cooled to 25° C. to 30° C. and the mixture was stirred for 30 to 45 minutes at 25° C. to 30° C. The solid obtained was filtered and was dried at 40° C. for 2 to 4 hours, to yield Bosentan monohydrate (60 gm).

Provenance & Evidence