Diethyl Oxalate → HCID 86746418, compound

Temperature

-20 °C

Tetramethylethylenediamine (TMEDA) (2.3 ml) and s-butyllithium (1.3M in cyclohexane, 11.7 ml) were added to anhydrous ether (8.0 ml) at -78° C. under nitrogen. A solution of 5-bromo-1,2,3,3a,8,8a-hexahydro-1,3a,8-trimethylpyrrolo[2,3-b]indole (3.57 g) in anhydrous ether (10 ml) was added to the resulting reaction mixture at -78° C. via canula and stirred at this temperature for 1 hour and at -20° C. for 1 hour. The solution was then added via canula to a -78° C. solution of diethyloxalate (5.2 ml) in anhydrous ether (30 ml) under N2. The resulting mixture was held at -78° C. for 30 min, -20° C. for 2 hours and room temperature for 30 min. Saturated ammonium chloride solution (10 ml) was added and the organic and aqueous phases separated. The organic phase was washed twice with brine, dried (Na 2 SO4), filtered and concentrated under vacuum. The crude residue was purified using preparative high performance liquid chromatography (HPLC), (silica gel, sample loaded and eluted with 2% methanol in ethyl acetate). Concentration of the appropriate fractions afforded 1.6 g of 1,2,3,3a,8,8a-hexahydro-α-oxo-1,3a,8-trimethyl-5-pyrrolo[2,3-b]indole acetic acid, ethyl ester, as an oil.

1. waitThe resulting mixture was held at -78° C. for 30 min, -20° C. for 2 hours and room temperature for 30 min
2. customthe organic and aqueous phases separated
3. washThe organic phase was washed twice with brine
4. dry with materialdried (Na 2 SO4)
5. filtrationfiltered
6. concentrationconcentrated under vacuum
7. customThe crude residue was purified
8. washhigh performance liquid chromatography (HPLC), (silica gel, sample loaded and eluted with 2% methanol in ethyl acetate)

ORD record

ord-320c82b535404d0287faa3bd32049255

Source dataset

uspto-grants-1993_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05264587