Triphenylphosphine → (S)-1-[4-(3-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid methyl ester

Participants

Reaction Steps

A solution 14.23 g (110.6 mmol) of 3-fluoro-benzylalcohol and 27.19 g (108.8 mmol) of triphenylphosphine in 150 ml of tetrahydrofurane is added dropwise within 50 min under a nitrogen atmosphere at 0° C. to a solution of 23.65 g (100.5 mmol) of (S)-1-(4-hydroxy-phenyl)-5-oxo-pyrrolidine-3-carboxylic acid methyl ester and 21.62 g (100.5 mmol) of diisopropyl azodicarboxylate in 200 ml of tetrahydrofurane. The mixture is left to warm to RT and stirring is continued for 18 hours. For the working-up, the mixture is evaporated under reduced pressure. The solid residue is triturated in 400 ml of ether to leave a white solid mainly consisting of the product and triphenylphosphinoxide. After filtration, the solid material is triturated in 100 ml of cold methanol to yield 23.5 g (68% of theory) of (S)-1-[4-(3-fluoro-benzyloxy)-phenyl]-5-oxo-pyrrolidine-3-carboxylic acid methyl ester as a white solid [MS: m/e=344 (M+H)+] together with traces of triphenylphosphine and diisopropyl hydrazodicarboxylate.

Provenance & Evidence