Trifluoroacetic acid → HCID 131720770, compound

Participants

Reaction Conditions

Reaction Steps

BOC-N(Et)Gly-(L)-Asp(OBzl)-(L)-Cha-NH2 is dissolved in dichloromethane (~1:12 wt/wt), and to that solution is added TFA at ambient temperature. This is then stirred until HPLC indicates complete reaction (3-5 hours). The solution is concentrated to about 1/2 volume at 40-45° C. To this warm solution is added MTBE (~1:10 wt/wt vs. BOC-N(Et)Gly-(L)-Asp(OBzl)-(L)-Cha-NH2) while maintaining the temperature >40° C. The mixture is slowly cooled to about 5° C. and stirred for 1 hour to ensure complete crystallization. The resulting solids are filtered, and washed with chilled MTBE. The solids are dried under reduced pressure and analyzed for content of TFA.N(Et)Gly-(L)-Asp(OBzl)-(L)-Cha-NH2 (HPLC wt/wt assay). Yield is generally nearly quantitative, purity >95A %.

Provenance & Evidence