The compound that exhibits the following spectral data is IR: ($\nu$) $1685\,\mathrm{cm^{-1}}$; ${}^{1}\mathrm{H}$ NMR: $\delta = 7.84$ (d, $J=8$ Hz, 2H), 7.60 (d, $J=8$ Hz, 2H), 3.65 (t, $J=7$ Hz, 2H), 3.18 (t, $J=7$ Hz, 2H), 2.25 (pentet, $J=7$ Hz, 2H) ppm; ${}^{13}\mathrm{C}$ NMR: $\delta = 28, 36.45, 128, 130, 133, 137, 197$ ppm; EI MS $m/z$: 200, 198 (1:1), 185, 183 (1:1)