2-Methyloxazolo[5,4-b]pyridine-5,6-dicarboxylic acid → 2-Methyloxazolo[5,4-b]pyridine-5,6-dicarboxylic anhydride

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Reaction Conditions

Reaction Steps

A suspension of 2-methyloxazolo[5,4-b-]pyridine-5,6-dicarboxylic acid (4.84 g, 0.0218 mol) in acetic anhydride (150 mL) is slowly heated to 70° C. at which point all the solids dissolve forming a yellow solution. The reaction mixture is heated at 70° C. overnight, cooled to room temperature, and concentrated in vacuo. Xylene is added to remove excess acetic anhydride by codistillation. 2-Methyloxazolo[5,4-b]pyridine-5,6-dicarboxylic anhydride is obtained as a pale yellow solid in 97% yield melting point 194°-196° C.

Provenance & Evidence