Ethylmorpholine → Methyl 4-{3-[2-(3-bromobenzoylamino)ethoxy]-7,12-dihydroxy-10,13-dimethylhexadecahydrocyclopenta[a]phenanthren-17-yl}pentanoate

Participants

Reaction Steps

932 mg of methyl 4-[3-(2-aminoethoxy)-7,12-dihydroxy-10,13-dimethylhexadecahydrocyclopenta[a]phenanthren-17-yl]pentanoate (Example 1d) and 402 mg of 3-bromobenzoic acid are dissolved in 20 ml of anhydrous DMF and first 656 mg of O[(cyano(ethoxycarbonyl)methylene)amino]-1,1,3,3-tetramethyluronium tetrafluoroborate (TOTU) (Proceedings of the 21st European Peptide Symposium, Peptides 1990, Editors E. Giralt and D. Andreu, Escom, Leiden, 1991) and then 760 μL of N-ethylmorpholine are added at 0° C. The reaction mixture is stirred at RT for 20.5 hours and then poured into 100 ml of a 10% aqueous NaHCO3 solution. It is extracted 3 times using 150 ml of EA each time. The extract is dried over Na2SO4 and the solvent is removed in vacuo. Chromatography on silica gel using EA yields 610 mg of a viscous oil.

Provenance & Evidence