反应详情

To a solution of 6 mg (0.018 mmol) of the acid 5-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-propanoic acid in anhy. methylene chloride under argon was added 10.3 mg (5 eq.) of N-hydroxysuccinimide (NHS) (Aldrich) followed by 8.6 mg (2.5 eq.) of 1-ethyl-3-(dimethylaminopropyl)carbodiimide hydrochloride (EDC.HCl) (Sigma). After stirring at RT under argon for 4 hr TLC indicated only traces of starting material were left. The reaction mixture was directly subjected to chromatography on silica gel plates, eluting with 50% EtOAc-hexane. The product band was isolated, washed with a little EtOAc, the washings stripped of solvent under reduced pressure and the residue dried under high vacuum to give 5 mg (65%) of 1-[3-(5-Hydroxy-2,2,4-trimethyl-7-pentyl-2H-1-benzopyran-3-yl)-1-oxopropoxy]-2,5-pyrrolidinedione as a foam. HR (+) FAB MS: Calc (M+H), 430.2230; Observed, 430.2266.

1. waitwere left
2. washeluting with 50% EtOAc-hexane
3. customThe product band was isolated
4. washwashed with a little EtOAc
5. customthe residue dried under high vacuum