Toluene → N-Boc-2-Maleimidoethylamine

Temperature

-78 °C

A toluene solution of Mitsunobu reagent (diethyl azodicarboxylate) (1.106 g/ml, 8.2 mmol, 1.29 ml) was gradually added to a tetrahydrofuran solution (25 ml) of triphenylphosphine (2.15 g, 8.2 mmol) at −78° C. To the thus obtained solution, a tetrahydrofuran solution (5 ml) of (2-hydroxyethyl)carbamic acid tert-butyl ester (1.32 g, 8.2 mmol) and maleimide (794 mg, 8.2 mmol) was added, followed by stirring at −78° C. for 5 minutes and further stirring at room temperature for 36 hours. The thus obtained reaction solution was concentrated, ether was added thereto, and the formed precipitate was removed by filtration. The thus obtained filtrate was concentrated, and the resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:1) to give 2-(maleimido)ethylcarbamic acid tert-butyl ester (531 mg, 2.53 mmol, yield 31%).

1. stirringfurther stirring at room temperature for 36 hours
2. customThe thus obtained reaction solution
3. concentrationwas concentrated
4. additionether was added
5. customthe formed precipitate was removed by filtration
6. concentrationThe thus obtained filtrate was concentrated
7. customthe resulting residue was purified by silica gel column chromatography (hexane:ethyl acetate=1:1)

ORD record

ord-cf68be2016d0498cb8219cfd186de7ab

Source dataset

uspto-grants-2009_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07569706B2