Proton sponge → HCID 11027464, compound

Participants

Reaction Steps

4.95 g (12.0 mmole) of 3S)-3-acetoxymethyl-5-amino-6-benzyloxy-1-t-butoxycarbonylindoline, 1.61 ml (14.4 mmole) of methyl 2-bromopropionate, and 3.09 g (14.4 mmole) of 1,8-bis(dimethylamino)naphthalene were heated to reflux in 18 ml of benzene at 90° C. for 50 hours. The reaction mixture was diluted with benzene, washed with water and saturated brine, dried over anhydrous sodium sulfate, and filtered, followed by condensation to give a residue. The residue was then purified by silica gel column chromatography with changing an eluate from hexane:ethyl acetate (4:1) to hexane:ethyl acetate (2:1) to give 5.82 g of (3S)-3-acetoxymethyl-5-[1-(methoxycarbonyl)ethyl]amino-6-benzyloxy-1-t-butoxycarbonylindoline. Yield, 97%. HRMS: 498.2366 calculated as C27H34N2O7 ; 498.2387 observed.

Provenance & Evidence