Trifluoroacetic acid → (R)-4-(tert-butyldimethylsilyloxy)-2-(5-fluoro-2-methoxyphenyl)pyrrolidine 2,2,2-trifluoroacetate

Participants

Reaction Steps

To a solution of (R)-tert-butyl 4-(tert-butyldimethylsilyloxy)-2-(5-fluoro-2-methoxyphenyl)pyrrolidine-1-carboxylate (2.648 g, 6.222 mmol) in CH2Cl2 (26 mL) at 0° C. was added TFA (9.3 mL). The resulting mixture was warmed to ambient temperature and stirred for 2 hours. The reaction mixture was concentrated under reduced pressure to give the crude material that was azeotroped with toluene-CH2Cl2 (2×) and dried under reduced pressure to provide (R)-4-(tert-butyldimethylsilyloxy)-2-(5-fluoro-2-methoxyphenyl)pyrrolidine 2,2,2-trifluoroacetate (assumed to be a mixture of cis and trans isomers; 2.92 g, 106.8% yield), which was used directly without further purification. LC/MS (ES+APCI) m/z=326.3 (M+H).

Provenance & Evidence