Trifluoroacetic acid → HCID 59855128, compound

Participants

Reaction Steps

Trifluoroacetic acid (21 mL) was added to a solution of protected ester 9.4 (21 g) in dry DCM (210 mL) with caution at 0° C. The mixture was brought to room temperature over 4 hours. The reaction mixture was concentrated under reduced pressure to provide a yellow oily residue, which was re-dissolved in DCM (200 mL) and washed with water, saturated NaHCO3, water and brine, and dried over Na2SO4. After filtration, the solvent was removed under reduced pressure, and the product was crystallized in EtOAc-hexane. The mother liquid was concentrated and flash chromatographed (silica gel, 50% EtOAc in hexane as eluant). The product, (±)-ethyl 3-(4-hydroxyphenyl)-3-(1-methyl-1H-imidazol-2-yl)propanoate (9.5) was obtained as a colorless crystal (combined yield 11 g). LC-MS ESI (pos.) m/e: 275 (M+H). 1H NMR (500 MHz) (CDCl3) δ 9.28 (s, 1H); 6.98-7.00 (m, 3H); 6.65-6.77(m, 3H); 4.41 (dd, J=9.0, 3.0 Hz, 1H); 3.96 (q, J=7.0, 2H); 3.39 (s, 3H); 3.19 (dd, J=16.0, 7.0 Hz, 1H); 2.78 (dd, J=16.0, 6.5 Hz, 1H); 1.80 (t, J=7.0 Hz, 3H).

Provenance & Evidence