[OH:1][C:2]1[C:7]2[C:8]([CH3:16])=[C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])[O:10][C:6]=2[CH:5]=[CH:4][CH:3]=1.[Cl-].[Al+3].[Cl-].[Cl-].[C:21](Cl)(=[O:23])[CH3:22].O>ClC(Cl)C>[C:21]([C:3]1[CH:4]=[CH:5][C:6]2[O:10][C:9]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[C:8]([CH3:16])[C:7]=2[C:2]=1[OH:1])(=[O:23])[CH3:22]
To a solution of ethyl 4-hydroxy-3-methylbenzofuran-2-carboxylate (220 mg, 1 mmol) in dichloroethane (10 ml) was added aluminum chloride (665 mg, 5 mmol). To the resulting brown solution was added acetyl chloride (0.178 ml, 2.5 mmol). The mixture was stirred for 5 hours at room temperature. Ice and water (20 ml) was added. The mixture was extracted with ethyl acetate. The extracts were dried and concentrated to a white solid which was then treated with 1 ml of 10% K2CO3 aqueous solution in 10 ml methanol for 2 hours. The resulting mixture was poured into 0.1N HCl (25 ml) and filtered. The solid obtained was recrystallized from ethyl acetate/toluene to give the title compound (130 mg, 50%).
Wird geladen…
