Metaperiodic acid → 5-Methoxy-3-pyridinecarboxaldehyde

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Reaction Steps

To an cooled solution (−78° C. internal temp) of 0.2 g of methyl 3-methoxypyrazine-2-carboxylate in 25 mL of toluene was added 3 mL of 1 M diisobutyl aluminum hydride in toluene. After stirring 10 min the reaction was quenched with 5 mL of water, allowed to warm to room temperature and dried with 5 g of MgSO4. Concentration under reduced pressure gave 0.2 g of (5-methoxypyridin-3-yl)methanol as an resin (MS (m+1)=140.1). The (5-methoxypyridin-3-yl)methanol (0.2 g) was taken up 10 mL of anhydrous acetonitrile and added to a stirred mixture of 0.5 g of periodic acid and 0.05 g of chromium (III) acetylacetonate in 10 mL of acetonitrile. After stirring for 5 hrs at room temperature, the mixture was concentrated on the rotovap and partitioned between 20 mL of saturated sodium carbonate and 3×50 mL of ethyl acetate. The combined extracts were dried over MgSO4 and concentrated under reduced pressure. The product was obtained as an orange-brown oil and was used without further purification: MS (m+1)=138.1.

Provenance & Evidence