2-[2-(Benzyloxy)ethoxy]ethan-1-ol → methyl (7R)-7-({2-[2-(benzyloxy)ethoxy]ethyl}amino)-14-cyclohexyl-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylate

Participants

Reaction Steps

[2-(benzyloxy)ethoxy]acetaldehyde was prepared by Swern oxidation of commercially available 2-[2-(benzyloxy)ethoxy]ethanol. A 0.15M solution of the foregoing aldehyde and methyl (7R)-7-amino-14-cyclohexyl-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylate (prepared as described in Example 1, Step 4) in CH(OMe)3 was stirred overnight at RT; the residue obtained after removing volatiles in vacuo was dissolved in MeOH (0.15M solution), NaCNBH3 (2.3 eq) was added and the mixture was left stirring for 4 h. All volatiles were evaporated and the residual material was dissolved in EtOAc and washed with sat. aq. NaHCO3 and brine. After drying over Na2SO4 all volatiles were evaporated in vacuo; FC (Biotage, PE/EtOAc 1:1 to 1:3 with 0.5% NEt3) afforded 35% of methyl (7R)-7-({2-[2-(benzyloxy)ethoxy]ethyl}amino)-14-cyclohexyl-7,8-dihydro-6H-indolo[1,2-e][1,5]benzoxazocine-11-carboxylate.

Provenance & Evidence