380631-18-5Relevant articles and documents
Synthesis of Acetyl and Iodo Derivatives of 4-Hydroxy-6-phenyl-6H-pyrano[3,2-c]pyridine-2,5-diones and 4-Hydroxy-1-phenylpyridin-2(1H)-ones
Nikam,Kappe
, p. 546 - 550 (2017/02/03)
A simple and efficient method has been described for the synthesis of acetyl and iodo derivatives of 4-hydroxy-6-phenyl-6H-pyrano[3,2-c]pyridine-2,5-diones 1 and 4-hydroxy-1-phenylpyridin-2(1H)-ones 5. Compounds 1 with phenyl and alkyl substituent at C(7) and C(8), respectively, can be easily acetylated by refluxing in a mixture of acetic acid and polyphosphoric acid to give 3-acetyl-4-hydroxy-6-phenyl-6H-pyrano[3,2-c]pyridine-2,5-diones 2 in excellent yields. Compounds 1 and 5 can be iodinated with iodine and anhydrous sodium carbonate in boiling dioxane to give 4-hydroxy-3-iodo-6-phenyl-6H-pyrano[3,2-c]pyridine-2,5-diones 3 and 4-hydroxy-3-iodo-1-phenylpyridin-2(1H)-ones 6, respectively, in good yields. The structures were confirmed using infrared, nuclear magnetic resonance, and elemental analysis.