Trifluoroacetic acid → (2E)-3-{4-[Cyclohexylidene(4-hydroxyphenyl)methyl]-2-fluorophenyl}-2-propenoic acid

Participants

Reaction Steps

Trifluoroacetic acid (1.5 mL) was added dropwise to 90 (180 mg, 0.551 mmol) dissolved in CH2Cl2 (3 mL) at 0° C. The reaction mixture was stirred at RT for 2 h and the volatiles were removed under reduced pressure. Water (30 mL) was added and the mixture was extracted with EtOAc (3×20 mL). The combined organic layers were washed with water (30 mL), brine (30), and dried over MgSO4. Concentration followed by recrystallization (EtOAc) afforded 99 mg (64%) of 91 as a pale yellow solid. 1H NMR (400 MHz, DMSO-d6): δ 1.52 (br s, 6H), 2.13 (br s, 4H), 6.51 (d, J=16.0 Hz, 1H), 6.67 (d, J=8.4 Hz, 2H), 6.85-6.91 (m, 4H), 7.59 (d, J=16.0 Hz, 1H), 7.72 (t, J=8.1 Hz, 1H), 9.36 (s, 1H), 12.51 (br s, 1H). LRMS (APCI): m/z 353 (M+H)+.

Provenance & Evidence