反应详情

Trifluoroacetic acid (10 ml) was added slowly to a solution of 2-[4-(4-Bromophenyl)piperazine-1-sulfonylmethyl]-3-methylbutyric acid tert-butyl ester (2 26 g) in dichloromethane (50 ml). After stirring at room temperature for 3.5 h, the solvents were removed under vacuum, and the residue azeotroped twice with 1:1 dichloromethane/hexane (30 ml). The residue was then dissolved in 1 M sodium hydroxide (20 ml) and washed with diethyl ether (50 ml). The aqueous phase was then acidified to pH 3-4 with citric acid and extracted with dichloromethane (60 ml, then 2×20 ml). The combined dichloromethane extracts were then washed with water (20 ml), saturated brine (20 ml), dried (MgSO4) and the solvents removed under reduced pressure to provide the title compound as a white solid (3 81 g, 79%).

1. customthe solvents were removed under vacuum
2. customthe residue azeotroped twice with 1:1 dichloromethane/hexane (30 ml)
3. dissolutionThe residue was then dissolved in 1 M sodium hydroxide (20 ml)
4. washwashed with diethyl ether (50 ml)
5. extractionextracted with dichloromethane (60 ml
6. washThe combined dichloromethane extracts were then washed with water (20 ml), saturated brine (20 ml)
7. dry with materialdried (MgSO4)
8. customthe solvents removed under reduced pressure