O[C:2]1[CH:3]=[C:4]([CH:10]=[CH:11][C:12]=1O)[C:5]([O:7][CH2:8][CH3:9])=O.[C:14]([O-:17])([O-])=[O:15].[K+].[K+].[CH2:20](Br)[C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1.[OH-:28].[K+]>C(C(C)=O)C.CO.O>[CH2:5]([O:7][C:8]1[CH:3]=[C:2]([CH:12]=[CH:11][C:9]=1[O:28][CH2:20][C:21]1[CH:26]=[CH:25][CH:24]=[CH:23][CH:22]=1)[C:14]([OH:17])=[O:15])[C:4]1[CH:10]=[CH:11][CH:12]=[CH:2][CH:3]=1
To 60 g (0.33 mole) of ethyl 3,4-dihydroxybenzoate in 50 ml of methyl ethyl ketone was added 105.5 g (0.76 mole) of K2CO3 and 168.8 g (0.76 mole) of benzyl bromide. The mixture was refluxed for 16 hours and filtered. Evaporation of the filtration gave an oil. This oil was mixed with 40 g of KOH, 350 ml of water and 350 ml of methanol and refluxed for 2.5 hours. The methanol was evaporated and the reaction mixture was acidified with concentrated HCl. The precipitate was filtered to give 101 g (92%) of the desired product; m.p. 184°-185° C. The NMR and IR spectra were consistent with the assigned structure.
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