反应详情

To a suspension of 4,5-diamino-1-(2-hydroxyethyl)pyrazole sulfuric acid salt (50.0 g) in chloroform (500 ml) were added 4-(dimethylamino)pyridine (2.54 g), triethylamine (116 ml) and 1,3-bis(tert-butoxycarbonyl)-2-(trifluoromethanesulfonyl)guanidine (106 g). The mixture was stirred under reflux for 2 hours. After cooling on an ice bath, the reaction mixture was washed successively with water, 4% aqueous citric acid solution, water and aqueous sodium hydrogen carbonate solution. The organic layer was dried over sodium sulfate, filtered and concentrated in vacuo. The residue was triturated with a mixed solvent of ethyl acetate (50 ml) and diethyl ether (200 ml) to give 5-amino-4-[2,3-bis(tert-butoxycarbonyl)guanidino]-1-(2-hydroxyethyl)pyrazole (50 g) as a solid.

1. temperatureunder reflux for 2 hours
2. temperatureAfter cooling on an ice bath
3. washthe reaction mixture was washed successively with water, 4% aqueous citric acid solution, water and aqueous sodium hydrogen carbonate solution
4. dry with materialThe organic layer was dried over sodium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was triturated with a mixed solvent of ethyl acetate (50 ml) and diethyl ether (200 ml)