HCID 23468823, compound → HCID 23468845, compound

Participants

Reaction Steps

1,600 ml of 70% sulfuric acid are added to 214 g (0.8 mol) of ethyl 3-methoxy-4-(1-methyl-2-oxopropoxy)-benzoate at room temperature. During this addition, the reaction mixture becomes dark-red to brown in colour. Thereafter, the reaction mixture is warmed to 60° for 4 hours. A brown crystalline sludge thereby gradually forms. The reaction mixture is allowed to cool to room temperature and is poured onto 2 kg of ice and extracted with ethyl acetate. The extract is washed twice with water and then 5 times with 500 ml of 0.5 N sodium bicarbonate solution each time and 3 times with 500 ml of 2 N sodium carbonate solution each time, dried over magnesium sulfate and evaporated completely under a waterpump vacuum. Chromatography on 1.5 kg of silica gel using chloroform which contains 2% of methanol gives ethyl 2,3-dimethyl-7-methoxy-5-benzofurancarboxylate, which, after recrystallisation from warm hexane, melts at 67°-68°.

Provenance & Evidence