Ethylene Glycol → 2-Pyridinyl-1,3-dioxolane

Beteiligte Stoffe

Reaktionsschritte

A mixture of pyridine-2-carboxaldehyde (151 g, 1.41 mol), ethylene glycol (157 mL), and 56 g (0.29 mol) of p-toluenesulfonic acid monohydrate in 1.4 L of toluene placed in a 5 L flask fitted with a Dean Stark trap was heated to reflux for 16 h, removing 50 mL of water. The mixture was concentrated in vacuo to a 800 mL volume, cooled, saturated sodium hydrogen carbonate solution was added (to pH 8-9), the layers were separated and the aqueous layer was washed with 100 mL of toluene. The combined organic layer was dried over magnesium sulfate, concentrated in vacuo, and distilled (with a short distilling head) to afford 119.5 g of 2-(1,3-dioxolan-2-yl)-pyridine (Formula V: R1 =H) as a pale oil, b.p. 100° C./1 mm.

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