Acetic Anhydride → (1R,4S)-1-acetylamino-4-(hydroxymethyl)-2-cyclopentene

Participants

Reaction Conditions

Reaction Steps

25 g (1R, 4s)-1-amino-4-(hydroxymethyl)-2-cyclopentene hydrochloride were dissolved in 182 ml of acetic anhydride, and at 0° C., a solution of 18.25 g of triethylamine in 60 ml of acetic anhydride were added thereto. The mixture was stirred at 80° C. for 3 h, then cooled to room temperature. The triethylamine hydrochloride was filtered off and washed with 120 ml of n-hexane. The filtrate was evaporated. 300 ml of toluene were added to the residue, and the mixture was stirred at room temperature in the presence of 5.2 g of activated carbon and 13 g of Celite for 20 min. The mixture was then filtered, and the filter cake was washed (3×40 ml of toluene), and the solvent was completely evaporated. 180 ml of methanol and 15.5 g of K2CO3 were added to the residue, and the mixture was stirred at room temperature for 10 h. The suspension was filtered off and the filtrate evaporated. The residue was suspended in 750 ml of isopropyl acetate and boiled in the presence of 0.5 g of activated carbon to reflux for 1.5 h. Following filtration of the activated carbon (70-80° C.), the filtrate was cooled at 0° C. overnight. The title compound was filtered, washed with 80 ml of cold isopropyl acetate and dried under reduced pressure to give 17.2 g of product. The yield was 66%.

Provenance & Evidence