Water → Ethyl 3-(4-tert-butoxycarbonylaminocyclohex-1-enyl)benzoate

Participants

Reaction Conditions

Reaction Steps

A solution of ethyl (4-hydroxycyclohex-1-enyl)benzoate obtained in Example (195a) (1 g, 4.06 mmol) in pyridine (20 mL) was cooled to 0° C. Methanesulfonyl chloride (628 μL, 8.12 mmol) was added at the same temperature, and the mixture was stirred at 0° C. for two hours. The reaction solution was diluted with ethyl acetate, washed with 1 N hydrochloric acid and brine, and dried over magnesium sulfate. Thereafter, the solvent was evaporated under reduced pressure. The resulting residue was dissolved in N,N-dimethylformamide (30 mL). Sodium azide (1.32 g, 20.3 mmol) was added at room temperature, and the mixture was stirred at 70° C. for 18 hours. The reaction solution was diluted with ethyl acetate, washed with brine, and dried over magnesium sulfate. Thereafter, the solvent was evaporated under reduced pressure. The resulting residue was dissolved in tetrahydrofuran (30 mL). Water (109 μL, 6.09 mmol) and triphenylphosphine (1.17 g, 4.47 mmol) were added at room temperature, and the mixture was stirred at room temperature for 18 hours. After 18 hours, di-tert-butyl dicarbonate (975 mg, 4.47 mmol) was added, and the mixture was stirred at room temperature for five hours. The reaction solution was diluted with ethyl acetate, washed with brine, and dried over magnesium sulfate. Thereafter, the solvent was evaporated under reduced pressure. The resulting residue was purified by silica gel column chromatography (elution solvent: hexane/ethyl acetate=2/1) to obtain 510 g of the title compound as a yellow oily substance (32%).

Provenance & Evidence