Dimethylformamide → HCID 18355159, compound

Temperature

0 °C

To a solution of 2,2,6,6-tetramethylpiperidine (1.97 g) in tetrahydrofuran (24.0 ml) was added dropwise n-butyllithium (6.8 ml, 1.64M solution in n-hexane) at −40° C. and the mixture was stirred at 0° C. for 30 minutes. A solution of methyl 1-methoxymethoxyindole-4-carboxylate (1.64 g) in tetrahydrofuran (12.0 ml) was added to the above solution at −60° C. and the solution was stirred at the same temperature for 30 minutes. A solution of N,N-dimethylformamide (662 mg) in tetrahydrofuran (9.0 ml) was added to the reaction mixture at −60° C. and the solution was stirred at the same temperature for 2 hours. The temperature was raised to −30° C. and the reaction was quenched with saturated ammonium chloride aqueous solution. The aqueous solution was extracted with ethyl acetate (80 ml) and the organic layer was washed with brine. Drying, filtering and removal of solvents afforded a crude product. The crude product was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=9:1) to give methyl 2-formyl-1-methoxymethoxyindole-4-carboxylate (1.15 g).

1. stirringthe solution was stirred at the same temperature for 30 minutes
2. stirringthe solution was stirred at the same temperature for 2 hours
3. temperatureThe temperature was raised to −30° C.
4. customthe reaction was quenched with saturated ammonium chloride aqueous solution
5. extractionThe aqueous solution was extracted with ethyl acetate (80 ml)
6. washthe organic layer was washed with brine
7. customDrying
8. filtrationfiltering
9. customremoval of solvents
10. customafforded a crude product
11. customThe crude product was purified by silica gel column chromatography (eluent; n-hexane:ethyl acetate=9:1)

ORD record

ord-2f5a0cc44a7d4ac8841a6b176f9934c4

Source dataset

uspto-grants-2001_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US06207693B1