Ethylene Glycol → 2-Bromo-5-(1,3-dioxolan-2-YL)pyridine

Participants

Reaction Steps

A mixture of 2-bromo-5-pyridinecarboxaldehyde (2 Scheme 27, 12.0 g, 64.5 mmol) and ethylene glycol (5.4 mL, 96.8 mmol) and p-toluenesulfonic acid (100 mg) in benzene (150 mL) was refluxed in a Dean Stark apparatus for 16 h. The reaction mixture was cooled to room temperature, and the solution was extracted with cold water/ethyl acetate. The organic layer was dried (Na2SO4) and concentrated. The crude product was purified by column chromatography (1:4 ethyl acetate/hexanes) to afford a orange colored oil (10.5 g, 70%); 1H NMR (300 MHz, CDCl3) δ 3.82-3.96 (4 H), 5.64 (s, 1 H), 7.34 (d, J=8.10 Hz, 1 H), 7.49 (dd, J=8.10 Hz, 1 H), 8.29 (d, J=2.10 Hz, 1 H); 13C NMR (75 MHz, CDCl3) 65.5 (2C), 101.2, 128.0, 133.4, 137.0, 142.8, 148.8. HRMS (EI) calcd for C8H8BrNO2 228.9738, found 230.9718.

Provenance & Evidence