反应详情

To N-(2-hydroxyethyl)iminodiacetic acid (3.55 g, 20 mmol) in 500 mL EtOH was added concentrated HCl (1.7 mL, 21 mmol). The mixture was stirred for 24 h at rt and concentrated. The residue was partitioned in diethyl ether (200 mL) and NaHCO3 (150 mL, 10% wt). After layer separation, the organic phase was washed with aqueous NaHCO3 (2×100 mL) and dried over Na2SO4 and concentrated and dried under high vacuum. To this crude product in 250 mL of dioxane was added 1.5 mL of HCl and the mixture was heated to reflux for 24 h. After removal of the solvent, the residue was chromatographed (dichloromethane/methanol) to afford a dark yellow oil (1.45 g). 1H-NMR (CD3OD, 300 MHz) δ (ppm): 4.40 4.37 (m, 2H), 4.18-4.11 (m, 2H), 3.60 (s, 2H), 3.29 (s, 2H), 2.89-2.86 (m, 2H), 1.25-1.20 (m, 3H); 13C-NMR δ (ppm) 169.4, 167.0, 68.6, 60.9, 57.0, 54.5, 48.2, 14.2. (ESI) m/z: 188 (M+H+, 100).

1. concentrationconcentrated
2. customThe residue was partitioned in diethyl ether (200 mL)
3. customAfter layer separation
4. washthe organic phase was washed with aqueous NaHCO3 (2×100 mL)
5. dry with materialdried over Na2SO4
6. concentrationconcentrated
7. customdried under high vacuum
8. additionTo this crude product in 250 mL of dioxane was added 1.5 mL of HCl
9. temperaturethe mixture was heated
10. temperatureto reflux for 24 h
11. customAfter removal of the solvent
12. customthe residue was chromatographed (dichloromethane/methanol)