Hydrogen Bromide → HCID 178440075, compound

Participants

Reaction Conditions

Reaction Steps

Trityl olmesartan medoxomil (250 g, 310 mmol) (97.3% area) is dissolved in THF (1560 ml) and 48 wt-% aqueous hydrobromic acid (70.6 ml, 625 mmol) is added slowly. The mixture is stirred for at 25° C. After 1 hour the precipitate forms. The mixture is stirred for 1 additional hour at 25° C., then cooled to −5° C. and stirred for 1.5 hours at −5° C. The precipitate is filtered. 940 ml of THF is added to the precipitate and the mixture is stirred for 1 h at 25° C. and then 1 hour at −5° C. Then precipitate is filtered off and washed with cold THF (150 ml). It is then dissolved in a mixture of water (875 ml) and acetone (440 ml). To a clear solution 5% aqueous solution of NaHCO3 is added to raise pH to 5.15. The mixture is stirred for 1 hour at room temperature and 1 hour at 0° C. The precipitate is filtered, washed with water and then recrystallised from a mixture of acetonitrile (280 ml) and water (70 ml) to give 124.5 g of olmesartan medoxomil (99.68% area).

Provenance & Evidence