1,4-Dioxane → 1-oxo-1,3-dihydroisobenzofuran-5-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

In a hydrogenator, 8.2 g (0.042 mole) of 5-chlorocarbonylphthalide, 50 ml of dioxane and 0.77 g of 5% Pd/BaSO4 are charged and the mixture is hydrogenated at 4 bar and 70° C. for 7 hours. After this period of time, the reaction no longer proceeds because of the co-precipitation of the formed product; thus, the hydrogenation is stopped, the mixture is diluted with 120 ml of tetrahydrofuran and stirred at 40° C. for 20 minutes. The solid is filtered off and the solution is concentrated to a little volume. The crystalline product is recovered by filtration and dried to give 3.3 g of 5-formylphthalide with a purity (HPLC)=82% (yield 40%).

Provenance & Evidence