Dicyclohexylcarbodiimide → HCID 178513960, compound

Participants

Reaction Conditions

Reaction Steps

In 26 ml of dry DMF was suspended 1.569 g of compound (4) and 1.187 ml of triethylamine was dropwise added slowly to the suspension at -15° to -10° C. After stirring the mixture at the same temperature for 30 minutes, insoluble matters were filtered off under cooling to obtain a clear filtrate. The filtrate was cooled to -10° C. and, a solution of 657.8 mg of compound (17) and 667 mg of HOBT in 20 ml of dry DMF was dropwise added gradually to the filtrate. Then, 861 mg of DCC was added thereto. After stirring the mixture for 2 hours at -10° to 0° C., the mixture was allowed to stand overnight in a refrigerator. The temperature was elevated to room temperature again and the precipitated crystals were filtered off. The solvent of the filtrate was removed by distillation under reduced pressure and the thus obtained residue was purified by column chromatography using 200 ml of silica gel (Wakogel C-200). By eluting with ethyl acetate-methanol-conc. ammonia water (60:30:3), 840 mg of Nα -[(S)-1-hydroxymethyl-4-oxo-2-azetidinylcarbonyl]-L-histidyl-L-prolinamide (18) was obtained.

Provenance & Evidence