p-Toluenesulfonic acid → N-[1-(6-Bromopyridin-2-yl)ethylidene]-2,6-diethylaniline

Participants

Reaction Steps

In argon atmosphere, a mixture of 6.00 g (30.0 mmol) of 1-(6-bromopyridin-2-yl)ethanone, 4.69 g (31.5 mmol) of 2,6-diethylaniline, 50 mg of TsOH, and 300 ml of toluene was refluxed for 2-3 h using a Soxhlet apparatus with an extraction thimble filled with anhydrous CaCl2. The reaction mixture was cooled to ambient temperature, passed through a short layer of silica gel 60 (40-63 um), and then evaporated to dryness. The crude product was recrystallized from 50 ml of methanol. Yield 6.20 g (63%) of a yellow crystalline solid. Anal. calc. for C17H19BrN2: C, 61.64; H, 5.78, N, 8.46. Found: C, 61.83; H, 5.88, N, 8.39. 1H NMR (CDCl3): δ 8.32 (dd, J=7.8 Hz, J=0.7 Hz, 1H, 3-H in pyridine), 7.65 (t, J=7.8 Hz, 1H, 4-H in pyridine), 7.57 (dd, J=7.8 Hz, J=0.7 Hz, 1H, 5-H in pyridine), 7.09-7.11 (m, 2H, 3, 5-H in 2, 6-Et2C6H3), 7.02 (m, 1H, 4-H in 2, 6-Et2C6H3), 2.33 (m, 4H, CH2Me), 2.16 (s, 3H, CH3C═N), 1.11 (t, J=7.6 Hz, 6H, CH2Me).

Provenance & Evidence