2,2-Dimethyl-1,3-dioxane-4,6-dione → HCID 22417853, compound

Participants

Reaction Conditions

Reaction Steps

In a three neck round-bottom flask equipped with a reflux condenser and a mechanical stirrer, a solution of 10.0 g (69.3 mmol) of 2,2-dimethyl-1,3-dioxan-4,6-dione (Meldrum's acid) and 46 mL (277 mmol) of triethyl orthoformate was treated with 11.1 g (72.7 mmol) of 2,4-dimethoxyaniline. The mixture was heated at 85° C. for two hours. Upon cooling to room temperature, the reaction mixture was diluted with isopropyl ether and filtered to furnish 18.7 g of 5-[(2,4-dimethoxyphenyl)aminomethylene]2,2-dimethyl-1,3-dioxan-4,6-dione as a bright orange solid. This solid was then added portionwise to 80 mL of a boiling solution of biphenyl and diphenyl ether/biphenyl, (Dowtherm, trademark). After the final addition heating was continued for just 5 minutes. After cooling to room temperature, the reaction mixture was stored in the refrigerator overnight, and then stirred with isopropyl ether for an hour. The solids were filtered and washed with isopropyl ether to afford 11.8 g (83%) of 6,8-dimethoxyquinolin-4-ol: m.p. 221°-224° C.

Provenance & Evidence