3-Chlorophthalide → Phthalide

Participants

Reaction Steps

As described in Example 1, an autoclave is charged with 110 g of 3-chlorophthalide, 5 g of palladium-on-charcoal catalyst (metal content 5%), 54 g of sodium acetate and 400 ml of glacial acetic acid, and treated for 1.5 h with hydrogen at 5 to 10 bars of pressure and 20° to 35° C. After filtration and working up by distillation, 76.5 g of phthalide is obtained, melting point 72°-73° C. (gas-chromatographic analysis 99.35).

Provenance & Evidence