3-(2,4-Difluorophenyl)acrylic Acid → 3-(2,4-difluorophenyl)propanoic Acid

Participants

Reaction Steps

A solution of 5.0 g (27.15 mmol) of 3-(2,4-difluorophenyl)acrylic acid in EtOH (50 mL) is hydrogenated over PtO2 catalyst under atmospheric pressure and stirred overnight at RT. After filtration to remove the catalyst, the filtrate is concentrated in vacuo to afford 3-(2,4-difluorophenyl)propanoic acid as a white solid: m.p. 104° C. 1H NMR (CDCl3, 400 MHz) δ 2.67 (t, 2H, J=7.6 Hz), 2.94 (t, 2H, J=7.6 Hz), 6.80 (m, 2H), 7.18 (dd, 1H, J=14.8 Hz and 8.0 Hz). The title A compound, (2,4-difluorophenyl)piperazin-1-yl-propanone hydrochloride is obtained analogously to the title B compound of Example 4 as a white solid: m.p=221° C. LC/MS (M+1=255.1). 1H NMR (DMSO-d6, 400 MHz) δ 2.66 (t, 2H, J=7.6 Hz), 2.81 (t, 2H, J=7.6 Hz), 3.01 (m, 2H), 3.05 (m, 2H), 3.69 (m, 4H), 7.02 (dt, 1H, J=8.4 Hz and 2.4 Hz), 7.18 (dt, 1H, J=10.0 Hz and 2 8 Hz), 7.29 (dd, 1H, J=15.6 Hz and 8.8 Hz), 9.65 (br s, NH). Anal. calculated for (C13H16F2N2O HCl+0.2 H2O): C, 53.05; H, 5.96; Cl, 12.04; F, 12.91; N, 9.52; O, 6.52. Found C, 53.01; H, 5.96; N, 9.74.

Provenance & Evidence