Ethylene Glycol → 2-(4-Bromothiophen-2-yl)-1,3-dioxolane

Participants

Reaction Steps

A benzene (55 mL) solution of 4-bromo-2-thiophene carboxaldehyde (9.76 g 51.09 mmol), ethylene glycol (8.55 mL, 153.26 mmol) and p-toluenesulfonic acid monohydrate (0.972 g, 5.11 mmol) was refluxed with azeotropic removal of H2O for 6 h and then cooled to ambient temperature. The reaction mixture was diluted with Et2O and the organics washed with sat'd NaHCO3, brine and then dried (MgSO4), filtered and concentrated. Chromatography on silica gel using 95:5 Hexanes:EtOAc eluted the product to provide the title compound upon concentration as a yellow oil (10.76 g 90% yield): 1H NMR (CDCl3, 400 MHz) δ 7.22 (s, 1H), 7.08 (s, 1H), 6.07 (s, 1H), 4.14–4.00 (m, 4H).

Provenance & Evidence