英文載せます。 A stirred mixture of 39g methylenedioxybenzene,48g propionic anhydride and 1.54g elemental iodine was held at reflux temperature with heating mantle for 3.5h The crude reaction mixture was freed of all volatiles that could be removed at 65"C,at the water pump,yielding 42g of aheavy black oil. The distillate smelled strongly of propionic acid. (Attempts to purify or decolorize this thick crude product by acid, base,or bisulfite washing,were not successful) The crude product was distilled at 0.1mm/Hg. At 600C a sizable quantity of clear colorless liquid distilled over (the temperature was maintained until the distillation was complete and the distillate was flamed into the traps.)
Between 100-125C apale brown fraction distilled over,waighing 28g. This was dissolved 200ml methylene chloride and decolorize by washing with 2×600ml water,each portion containing 1g sodium bisulfite. Removal of the organic solvent under vacuum gave 27.1g of a pale brown residue which was again distilled at 0.2mm/Hg to give a fraction boiling at 90-1150C that was essentially white. This,on cooling,crystallized to give 3,4-methylenedioxypropiophenone as amass of off-white solids,weighing 24.46g.