HCID 2752581, compound → Phthalide

Participants

Reaction Conditions

Reaction Steps

In the manner described in Example 1, the autoclave is filled with 86.4 g of 3-acetoxyphthalide, 400 ml of methanol and 10 g of palladium-on-charcoal catalyst (Pd content 5 wt%), raised to 10 bars with hydrogen, and slowly heated to 35° C. The consumed hydrogen is first replaced by addition in the range up to 10 bars, and then again in the range up to 20 bars and after the reaction rate has decreased. After 3 hours the pressure remains constant. The catalyst is filtered off and the remaining solution is concentrated at 70° C. and 20 Torr in a rotary thin film evaporator. The residue, still smelling slightly of acetic acid, is fractionally distilled between 99° and 103° C. at 0.5 Torr, and the distillate is recrystallized from water. 54 g (90.05% of the theory) of phthalide of a melting point of 72.5° C. is obtained.

Provenance & Evidence