Water → 2-(3-Bromophenyl)-1,3-dioxane

Participants

Reaction Steps

A solution of 3-bromobenzaldehyde (1, 18.5 g, 100 mmol), propane-1,3-diol (9.1 g, 120 mmol) and p-toluenesufonic acid monohydrate (0.1 g, 0.5 mmol) in toluene (200 mL) was refluxed with azeotropical removal of water using a Dean-Stark water separator for 15.5 h. The reaction mixture was cooled to room temperature, washed with 5% potassium carbonate solution (100 mL) and water (2×100 mL), dried over sodium sulfate and filtered. The filtrate was concentrated to afford the title compound (24.8 g, 100%): 1H NMR (500 MHz, CDCl3) δ 7.66 (t, J=1.8 Hz, 1H), 7.46 (ddd, J=7.9, 2.0, 1.1 Hz, 1H), 7.40 (br d, J=7.9 Hz, 1H), 7.23 (t, J=7.9 Hz, 1H), 5.46 (s, 1H), 4.28-4.25 (m, 2H), 4.00-3.95 (m, 2H), 2.26-2.17 (m, 1H), 1.47-1.43 (m, 1H); ESI MS m/z 243, 245 [M+H]+.

Provenance & Evidence