Trifluoroacetic acid → HCID 88230495, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of the compound prepared in Step 5, above (3.2 g, 17 mmol), PPh3 (6.06 g, 22 mmol), and N,O-di-tert-butoxycarbonylhydroxylamine (4.5 g, 18 mmol) in THF (15 ml), cooled to −40° C., was added dropwise a solution of diethylazodicarboxylate (3.8 ml, 22 mmol) in THF (10 ml). The reaction mixture was warmed to room temperature overnight and the solvent removed under reduced pressure. Chromatography on silica gel (ethyl acetate/hexane, 1:9) gave 6.7 g of the crude N,O-di-tert-butoxycarbonyl-N-[cis-3-(3-fluorophenyl)cyclopentyl]hydroxylamine. To a stirred solution of the protected hydroxylamine obtained as above in CH2Cl2 (40 ml), cooled to 0° C., was slowly added trifluoroacetic acid (12.5 ml). The reaction mixture was allowed to warm to room temperature for 6 hours and then solvent was evaporated off. The resultant residue was covered with saturated aqueous NaHCO3 (50 ml) and extracted with CH2Cl2 (2×100 ml). The combined extracts were washed with brine (50 ml) and dried over MgSO4, and solvent was removed under reduced pressure. Chromatography on silica gel (ethyl acetate/hexane, 1:2) afforded the title compound (1.9 g, 64% yield) as a yellow solid.

Provenance & Evidence