Ethylene Glycol → 4-(1,3-dioxolan-2-yl)pyridine

Participants

Reaction Steps

A stirred solution of pyridine-4-carboxaldehyde (8.7 ml, 90 mmol), ethylene glycol (10 ml, 180 mmol) and p-toluene sulfonic acid (18.8 g, 99 mmol) in benzene (70 ml) was refluxed overnight. A Dean-Stark apparatus was used to remove water azeotropically from the reaction. After ˜15 h the mixture was cooled, then made basic with aq. NaOH (20% w/v, ˜30 ml). The benzene layer was isolated and the aqueous layer was washed with dichloromethane until no more product came out (˜5×60 ml). The combined organic phases were dried (Na2SO4) and solvent removed in vacuo to give the pure 4-(1,3 dioxolan-2-yl) pyridine [Registry No. 61379-59-7] as a pale yellow liquid that solidified under vacuum (12.57 g, 92%). 1H NMR (300 MHz, CDCl3): δ 4.06 (4H, m, O—(CH2)2—O), 5.82 (1H, s, O—CH—O), 7.39 (2H, d, J=6-Hz, H-3, H-5), 8.63 (2H, d, J=6 Hz, H-2, H-6) ppm.

Provenance & Evidence