反应详情

Referring to Scheme 4, to a solution of 1.74 g (10 mmol) of tert-butyl hydrogen succinate (Buchi, G.; Roberts, C. J. Org Chem., 33:460, 1968) and 1.15 g (10 mmol) of N-hydroxy-succinimide in anhydrous tetrahydrofuran (20 ml) was added 2.06 g (10 mmol) of 1,3-dicyclohexylcarbodiimide. After stirring at room temperature overnight, the reaction was filtered to remove the dicyclohexylurea by-product. The filtrate was concentrated in vacuo to give a residue. Chromatography on silica gel using ethyl acetate-hexane (1:1), provided 2.3 g (84% yield) of tert-butyl succinimidyl succinate (4a) as a white solid. TLC: Rf 0.50 (ethyl acetate-hexane 1:1); NMR (d6 -DMSO) a 1.39(s, 9H), 2.56(m, 2H), 2.80(bs, 4H), 2.86 (m, 2H).

1. filtrationthe reaction was filtered
2. customto remove the dicyclohexylurea by-product
3. concentrationThe filtrate was concentrated in vacuo
4. customto give a residue