Dicyclohexylcarbodiimide → HCID 22952776, compound

Participants

Reaction Steps

Boc-trans-4-hydroxy-L-proline (3.5 kg) and pentafluorophenol (3.06 kg) were dissolved in ethyl acetate (52 L). The solution was treated with a solution of dicyclohexylcarbodiimide (3.43 kg) in ethyl acetate (8 L) and the mixture was stirred at room temperature for 2 hours. The resulting slurry was cooled to 0° C., filtered and the solids washed with ethyl acetate (15 L). The filtrate was evaporated at atmospheric pressure to a volume of 10 L and diluted with hexane (100 L). The resulting mixture was stirred at room temperature overnight and then cooled to 0° C. for 1 hour. The solid was collected by filtration, washed with cold (° C.) 10:1 hexane/ethyl acetate (15 L) and dried at 45° C. in vacuo to afford the title compound as a white crystalline solid. Yield: 5.478 kg, 91%. HPLC; >99 A %.

Provenance & Evidence