L-Aspartic Acid → N-(tert-butoxycarbonyl)-L-aspartic acid

To a solution of 1.33 g (10 mmol) of L-aspartic acid in a dioxane/water (1:1) mixture (30 ml), 4.2 ml (30 mmol) of triethylamine are added, and the mixture is stirred until solution is complete (approximately 10 min). 2.85 g (10 mmol) of tert-butyl 1,2,2,2-tetrachloroethyl carbonate are then added and the mixture is stirred for 6 hours at 20° C. 50 ml of water are then added and the mixture is extracted with 2×20 ml of ethyl acetate. The aqueous phase is acidified (pH 2-3) with NHCl, and then extracted with 3×30 ml of ethyl acetate. The extract is washed with saturated NaCl solution, dried over MgSO4 and evaporated. The product obtained is crystallised in ethyl acetate and petroleum ether. 1.4 g (60% yield) of the expected acid is obtained. ##STR60##

1. custom(approximately 10 min)
2. stirringthe mixture is stirred for 6 hours at 20° C
3. extractionthe mixture is extracted with 2×20 ml of ethyl acetate
4. extractionextracted with 3×30 ml of ethyl acetate
5. washThe extract is washed with saturated NaCl solution
6. dry with materialdried over MgSO4
7. customevaporated
8. customThe product obtained
9. customis crystallised in ethyl acetate

ORDレコード

ord-0c0661338a584907b09ee85e49489e40

出典データセット

uspto-grants-1988_02

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US04725680