Diisopropylethylamine → N-[[1-[(2-Furanylcarbonyl)amino]cyclohexyl]carbonyl]-L-valinol

Participants

Reaction Steps

A solution of 8.81 ml (50.6 mmol) of N,N-diisopropylethylamine and 2.09 g (20.2 mmol) of L-valinol in 10 ml of methylene chloride was added to a solution of 3.71 g (16.9 mmol) of 2-(2-furanyl)-3-oxa-1-azaspiro[4.5]dec-1-en-4-one in 100 ml of toluene, and the mixture was refluxed under heating for 14 hours. The reaction solution was concentrated under reduced pressure, ethyl acetate was added to the residue, and the mixture was washed with water, a 10% aqueous potassium hydrogensulfate solution, a saturated aqueous sodium hydrogencarbonate solution, and then saturated brine. The organic layer was dried with anhydrous sodium sulfate, and the solvent was distilled off under reduced pressure. Ethyl acetate was added to the residue, and the mixture was stirred overnight. The obtained crystal was collected by filtration to give 4.06 g (74.7%) of the title compound.

Provenance & Evidence