[OH:1][C:2]1[CH:11]=[CH:10][C:5]2[C:6](=[O:9])[CH2:7][O:8][C:4]=2[CH:3]=1.C(=O)([O-])[O-].[K+].[K+].[CH2:18](Br)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1.O>CN(C=O)C>[CH2:18]([O:1][C:2]1[CH:11]=[CH:10][C:5]2[C:6](=[O:9])[CH2:7][O:8][C:4]=2[CH:3]=1)[C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1To a stirred solution of 6-hydroxy-3-oxo-2,3-dihydrobenzofuran of Example 6(a) (32 kg, 213 moles) in DMF (192 L) was added potassium carbonate (31.0 kg, 224 moles). After stirring for 5 min. at room temperature, benzyl bromide (145.2 kg, 264 moles) was added and the resulting mixture was stirred for 2 hours at room temperature. The mixture was poured into water (651 L), stirred for 30 minutes and the product collected by centrifugation. The crude solid was washed with water (580 L), 80% ethanol (100 L) and dried under vacuum to afford the desired product (49.1 kg; 95%) which was used without any further purification.
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