Cinchonidine → HCID 24959563, compound

Participants

Reaction Steps

To a solution of 1 (9.38 g, 29.7 mmol) in 2-propanol (150 ml), cinchonidine (8.73 g, 29.7 mmol) was added under vigorous stirring and the resulting mixture was left under reflux until to complete dissolution. After cooling at room temperature the formed precipitate was filtered off and the mother liquors were crystallized again from 2-propanol (50 mL). The collected precipitated salts (8.72 g) were dissolved in water (70 mL) and 37% HCl (2 mL) was added; the aqueous layer was extracted with CH2Cl2 (2×70 mL), dried over Na2SO4 and evaporated under vacuum to give the pure (2S)-2-fluoro-2-(4-{[(trifluoromethyl)sulfonyl]oxy}phenyl)propanoic acid (3.7 g, 11.7 mol) as pale brown solid. Yield 79%. mp 91-94° C. e.e. 96% (HPLC). [α]D=+19.8 (c=0.6; CH3OH). 1H-NMR (CDCl3) δ 7.70 (d, 2H, J=7 Hz), 7.40 (d, 2H, J=7 Hz), 2.00 (d, 3H, J=23 Hz).

Provenance & Evidence