Bromoacetonitrile → 1-(1,1-Dimethylethyl) 2-methyl (2R,5R)-2-(cyanomethyl)-5-(4-{[(2-fluorophenyl)methyl]oxy}phenyl)-1,2-pyrrolidinedicarboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 1-(1,1-dimethylethyl) 2-methyl (2S,5R)-5-(4-{[(2-fluorophenyl)methyl]oxy}phenyl)-1,2-pyrrolidinedicarboxylate (D34, 45 g) in dry THF (450 mL) previously cooled to −65° C., was added 1M LiHMDS in THF (115 mL) dropwise. The resulting solution was stirred at −35° C. for 30 minutes. Then the mixture was again cooled to −65° C. and bromoacetonitrile (22 mL) dissolved in dry THF (180 mL) was added. The mixture was left stirring for a further 30 min at the same temperature. The reaction was quenched with saturated ammonium chloride solution (675 mL), THF was evaporated in vacuo and the crude mixture was extracted with EtOAc (2×675 mL). The organic layer was evaporated and the crude material was purified by chromatography on silica gel using cyclohexanes and ethyl acetate (8:2) affording the title compound (51.3 g) as a yellow thick oil.

Provenance & Evidence