Water → HCID 21186768, compound

Participants

Reaction Conditions

Reaction Steps

Ethyl 2-methyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carboxylate N-oxide (8.00 g, 32.1 mmol) was dissolved in acetic anhydride (56.0 ml) and heated under reflux for 1.5 hours. After cooling, excess acetic anhydride was evaporated under reduced pressure, the thus obtained residue was mixed with ice water and 40% sodium hydroxide aqueous solution and extracted with ethyl acetate, and the resulting organic layer was washed with water and saturated brine in that order and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure, and the thus obtained reaction product (10.27 g, 32.1 mmol) was dissolved in methanol (40.0 ml), mixed with potassium carbonate (4.88 g) and stirred at 0° C. for 30 minutes. The reaction solution was mixed with water and ethyl acetate, and the thus precipitated crystals were collected by filtration to obtain pale yellow powder of 6,7,8,9-tetrahydro-5H-cyclohepta[b]pyrido[3,2-c]furan-3-one (2.69 g, 41.3%) as a low polar component The resulting filtrate was extracted with ethyl acetate, and the thus obtained organic layer was washed with water and saturated brine in that order and dried over anhydrous sodium sulfate. By evaporating the solvent under reduced pressure, methyl 9-hydroxy-2-methyl-6,7,8,9-tetrahydro-5H-cyclohepta[b]pyridine-3-carboxylate (4.20 g, 55.7%) was obtained in the form of white amorphous as a high polar component.

Provenance & Evidence