1,1'-Carbonyldiimidazole → (2r)-6-Hydroxy-2,5,7,8-tetramethyl-n-[(3s)-2-oxotetrahydro-3-furanyl]-3,4-dihydro-2h-chromene-2-carboxamide

Temperature

23 °C

A solution of 1.82 g (7.27 mmoles) of (R)-Trolox and 1.18 g (7.27 mmoles) of 1,1′-carbonyldiimidazole (CDI) in 15 ml of anhydrous THF is stirred for 1 hour at 23° C., before adding a solution of 1 g (7.27 mmoles) of (S)-2-amino4-butyrolactone hydrochloride and 1.27 ml (7.27 mmoles) of N,N-diisopropylethylamine (DIEA) in 15 ml of anhydrous DMF. The reaction mixture is stirred for 15 hours at 23° C. and finally concentrated to dryness under vacuum. The residue is dissolved in 100 ml of AcOEt and the organic solution is washed successively with 50 ml of 1N aqueous HCl, 50 ml of H2O, 50 ml of a saturated aqueous solution of NaHCO3, 50 ml of H2O and finally 50 ml of salt water. After drying over MgSO4, the organic solution is filtered and concentrated to dryness under vacuum. The residue is taken up in 50 ml of Et2O, followed by agitating and filtering. After rinsing with 2×25 ml of Et2O, the white powder, obtained is dried under vacuum. Melting point: 195-196° C.

1. concentrationfinally concentrated to dryness under vacuum
2. dissolutionThe residue is dissolved in 100 ml of AcOEt
3. washthe organic solution is washed successively with 50 ml of 1N aqueous HCl, 50 ml of H2O, 50 ml of a saturated aqueous solution of NaHCO3, 50 ml of H2O and finally 50 ml of salt water
4. dry with materialAfter drying over MgSO4
5. filtrationthe organic solution is filtered
6. concentrationconcentrated to dryness under vacuum
7. stirringby agitating
8. filtrationfiltering
9. washAfter rinsing with 2×25 ml of Et2O
10. customthe white powder, obtained
11. customis dried under vacuum

ORD record

ord-0f28cd1fb4ed4c7bbba56e980a1884a0

Source dataset

uspto-grants-2004_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06747024B1