5-Chlorocarbonylphthalide → 1-oxo-1,3-dihydroisobenzofuran-5-carbaldehyde

Participants

Reaction Conditions

Reaction Steps

To a solution of 8.58 g (0.043 mole) of 5-chlorocarbonylphthalide in 120 ml of N,N-dimethylacetamide in a hydrogenator 1 g of 5% Pd/BaSO4 is added and hydrogen at 2.5 bar is charged thereinto. The mixture is heated to 60° C., kept at this temperature for 40 hours at 2.5÷3 bar, then cooled, filtered to remove the catalyst and concentrated under vacuum at 75° C. The residue is taken up with 50 ml of deionized water, then the suspension is neutralized with 10% ammonium hydroxide solution to a pH=7.5 and the product is filtered to give 4.4 g (63%) of 5-formylphthalide with m.p.=162÷163° C.

Provenance & Evidence