[C:1]([C:9]1[O:10][C:11]2[CH:17]=[CH:16][C:15]([Br:18])=[CH:14][C:12]=2[CH:13]=1)(=O)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.NN.C(O)COCCO.[OH-].[K+]>O>[CH2:1]([C:9]1[O:10][C:11]2[CH:17]=[CH:16][C:15]([Br:18])=[CH:14][C:12]=2[CH:13]=1)[C:2]1[CH:3]=[CH:4][CH:5]=[CH:6][CH:7]=1A mixture of 42.2 g. (0.14 mol.) of 2-benzoyl-5-bromobenzofuran and 35 ml. of 98% hydrazine in 70 ml. of diethylene glycol is warmed for a few minutes on a steam bath. Then 23.3 g. of potassium hydroxide is added and the reaction mixture is refluxed for two hours. After cooling, water is added to the mixture and the resulting aqueous solution is extracted with benzene. The extract is washed with water, 10% aqueous hydrochloric acid and water, dried (MgSO4) and concentrated to yield 2-benzyl-5-bromobenzofuran.
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