Ethylene Glycol → 2-(4-Bromophenyl)-2-methyl-1,3-dioxolane

Participants

Reaction Steps

A mixture of 4-bromoacetophenone (1 Scheme 19, 20.0 g, 0.1 mol) and ethylene glycol (12.5 g, 0.2 mol) and p-toluenesulfonic acid (200 mg) in benzene (400 mL) was refluxed in a Dean Stark apparatus for 6 h. The reaction mixture was cooled to room temperature, and the solution was extracted with H2O/ethyl acetate. The organic layer was washed with brine, dried (Na2SO4), and concentrated to give a colorless oil (23 g, 96%); 1H NMR (300 MHz, CDCl3) δ 1.63 (s, 3 H), 3.76 (m, 2 H), 4.04 (m, 2 H), 7.37 (d, J=8.40 Hz, 2 H), 7.47 (d, J=8.40 Hz, 2 H); 13C NMR (75 MHz, CDCl3) 27.6, 64.5 (2C), 108.4, 121.9, 127.2 (2C), 131.4 (2C), 142.5

Provenance & Evidence