Trifluoroacetic acid → 4-(Prop-2-en-1-yl)benzaldehyde

Participants

Reaction Steps

5-Allyldipyrromethane (24). Following a standard procedure,40,41 a solution of 3-butenal diethylacetal (4.00 g, 27.7 mmol) in pyrrole (194 mL, 2.77 mol) at room temperature under argon was treated with TFA (467 μL, 2.77 mmol) for 10 min. TEA (221 μL, 2.77 mmol) was added. The mixture was concentrated under high vacuum. The residue was chromatographed [silica, hexanes/ethyl acetate (4:1)] to afford a pale orange oil (1.85 g, 36%): 1H NMR δ 2.86 (t, J=8.0 Hz, 2H), 4.11 (t, J=8.0 Hz, 1H), 5.02-5.12 (m, 2H), 5.83 (m, 1H), 6.08 (s, 2H), 6.15 (m, 2H), 6.65 (m, 2H), 7.83 (br s, 2H); 13C NMR δ 37.3, 38.7, 105.6, 107.6, 116.3, 117.1, 132.8, 136.2; FABMS obsd 187.1230, calcd 187.1235 [(M+H)+], (M=C12H14N2).

Provenance & Evidence