Preparation of dimethyl FDCA from methyl 5-formyl-2- furoate: A 15 niL glass liner was charged with a magnetic stirring bar, methyl 5- formyl-2-furoate (117 mg, 0.76 mmol), methanol (10 mL) and sodium methoxide (4 mg, 0.076 mmol) to give a clear solution. A 1.2 wt% Au/Ti02 (41.5 mg, 2.53 |ì|é|?|? Au) catalyst was added to give a purple suspension and the vial was placed in a 75 mL Parr Hastelloy C-276 reactor. The reactor was closed and flushed 3x with compressed air and then pressurized at 4.6 bar. Stirring was started (600 rpm) and the reaction was allowed to proceed at room temperature. After 19 h, the reaction had consumed 0.25 bar of air and the reactor was opened. The reaction mixture was filtered over Celite to remove the catalyst, which was washed with a httle methanol and dichlorom ethane. The combined organic layers were washed with water, dried over MgS04, filtered, and the solvent was removed under reduced pressure. 2,5-FDCA dimethyl ester was obtained as light yellow crystals (106 mg, yield 76%).
