2,2,2-Trifluoroethyl formate → methyl(7R)-14-cyclohexyl-7-{methyl[3-(methylamino)propyl]amino}-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylate

Participants

Reaction Steps

A solution of methyl(7R)-7-[(3-aminopropyl)(methyl)amino]-14-cyclohexyl-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylate (0.16 M) in THF was treated dropwise with 2,2,2-trifluoroethyl formate (1.3 eq.) and stirred overnight at RT. The volatiles were removed in vacuo and the residue dissolved (0.08 M) in THF and treated dropwise with BH3-DMS complex (2 M in THF; 10 eq.). The resulting solution was stirred at RT for 3 h. The reaction was quenched by the careful addition of HCl/MeOH (1.25 M) and the resulting solution refluxed for 2 h. The volatiles were then removed in vacuo and the residue partitioned between sat. aq. NaHCO3 and EtOAc. The combined organics were washed with brine, dried (Na2SO4), filtered and concentrated in vacuo. The crude material was purified by FC (EtOAc/MeOH/Et3N 90:8:2) affording the product as a pale orange solid (80% overall for steps 2, 3, 4, 5). (ES) m/z 490 (M+H)+.

Provenance & Evidence