Phenol → methyl (S)-2-tritylamino-3-phenoxypropionate

Participants

Reaction Conditions

Reaction Steps

2.8 g of trt-Ser-OMe (Bachem), 0.75 of phenol, and 2.25 g of triphenylphosphine were dissolved together in 60 ml of THF, absolute, and treated dropwise with 1.49 g of diethyl azodicarboxylate at 0° C. in the course of 30 min. The reaction mixture was stirred at 0° C. for 30 min and warmed to RT (about 1 h). For working-up, the solvent was removed under reduced pressure and the crude product was purified by chromatography on silica gel (heptane/ethyl acetate=1.5/1). The methyl (S)-2-tritylamino-3-phenoxypropionate thus obtained crystallized slowly in long needles, and was heated under reflux for 1 h in 5 M HCl to remove the protective groups. The reaction solution was evaporated to dryness under reduced pressure by coevaporating a number of times with toluene and the residue was recrystallized from a little tert-butanol.

Provenance & Evidence