反应详情

To a mixture of 4-(tert-butoxycarbonylamino)-2-nitrobenzoic acid in 60 ml of dichloromethane were added 4.8 g of N,N,N′,N′-tetramethyl-O-(1H-benzotriazol-1-yl)-uronium-hexafluorophosphate. After stirring for 15 min. a mixture of 3.8 g of L-glutamic acid-di tert.-butylester hydrochloride in 60 ml dichloromethane and 3 ml triethylamine was added dropwise. After stirring for 20 hours at room temperature, the mixture was filtered and the filtrate was washed five times with 10% aqueous citric acid, four times with 5% aqueous sodium carbonate solution and two times with water. The organic layer was dried over magnesium sulphate and concentrated in vacuum to give 6.3 g of di-tert-butyl N-(4-(tert-butoxycarbonylamino)-2-nitrobenzamido)-L-glutamate as a yellow foam. This was directly used in example 3.

1. additionwas added dropwise
2. stirringAfter stirring for 20 hours at room temperature
3. filtrationthe mixture was filtered
4. washthe filtrate was washed five times with 10% aqueous citric acid, four times with 5% aqueous sodium carbonate solution and two times with water
5. dry with materialThe organic layer was dried over magnesium sulphate
6. concentrationconcentrated in vacuum