1-Aminocyclohexanecarboxylic acid → 2-Cyclopentyl-3-oxa-1-azaspiro[4.5]dec-1-en-4-one

Participants

Reaction Steps

1.98 g (15 mmol) of cyclopentanecarbonyl chloride was added to a solution of 2.16 g (15 mmol) of 1-aminocyclohexanecarboxylic acid and 4.8 g (45 mmol) of sodium carbonate in 50 ml of ethyl acetate-50 ml of water under ice-cooling. After the mixture was stirred at room temperature overnight, ethyl acetate was added thereto, and the mixture was washed with a 10% aqueous potassium hydrogensulfate solution, a saturated aqueous sodium bicarbonate solution and then saturated brine. After the obtained organic layer was washed with saturated brine, it was dried with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure, methylene chloride was added thereto, and 1.59 g (8.3 mmol) of 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride was added under ice-cooling. After the mixture was stirred at room temperature overnight, the reaction solution was concentrated under reduced pressure, ethyl acetate was added thereto, and the mixture was successively washed with water, a 10% aqueous potassium hydrogensulfate solution, a saturated aqueous sodium hydrogencarbonate solution and saturated brine, followed by drying with anhydrous sodium sulfate. The solvent was distilled off under reduced pressure to obtain 1.41 g (42%) of the title compound.

Provenance & Evidence