3-(3-(1,3-Dioxoisoindolin-2-yl)propyl)benzaldehyde → (E)-2-(3-(3-(2-trifluoromethylstyryl)phenyl)propyl)isoindoline-1,3-dione

Participants

Reaction Steps

2-Trifluoromethylbenzyltriphenylphosphonium bromide was coupled with phthalimide 29 following the method used in Example 44 except that the reaction was conducted at −78° C. instead of 0° C. before warming to room temperature. Purification by flash chromatography (10 to 40% EtOAc-hexanes gradient) gave (E)-2-(3-(3-(2-trifluoromethylstyryl)phenyl)propyl)isoindoline-1,3-dione (0.0797 g, trans-/cis-isomer ratio 15.6:1) as an oil and (Z)-2-(3-(3-(2-trifluoromethylstyryl)phenyl)propyl)isoindoline-1,3-dione (0.1139 g, trans-/cis-isomer ratio 8.1:1) as an oil. Yield (0.1936 g total, 83%): Trans-isomer: 1H NMR (400 MHz, CDCl3) δ 7.69-7.73 (m, 2H), 7.68 (d, J=7.6 Hz, 1H), 7.56-7.63 (m, 3H), 7.45 (t, J=7.6 Hz, 1H), 7.34 (dq, J=16.0, 2.0 Hz, 1H), 7.21-7.28 (m, 3H), 7.14-7.19 (m, 1H), 7.05 (d, J=7.6 Hz, 1H), 6.93 (d, J=16.4 Hz, 1H), 3.69 (t, J=7.2 Hz, 2H), 2.64 (t, J=7.2 Hz, 2H), 1.95-2.04 (m, 2H).

Provenance & Evidence