1,2,6,7-Tetrahydro-8H-indeno[5,4-b]furan-8-one

196597-77-0

196597-78-1

4,5-Dibromo-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one (280 kg, 843 mol) was used as a raw material, mixed with anhydrous sodium acetate (173 kg, 2109 mol) and methanol (6384 L). After the reaction system was replaced with nitrogen, 10% Pd/C catalyst (30.8 kg, dry weight) was added. Subsequently, the reaction mixture was pressurized to 0.29 to 0.49 MPa under a hydrogen atmosphere and catalytically reduced for 8 hours at about 40°C with a stirring rate such that the total gas-liquid mass transfer coefficient, KLa (1/hr), was about 15. Upon completion of the reaction, the catalyst was removed by filtration and the filtrate was concentrated under reduced pressure. Water was added to the concentrated residue, concentrated again under reduced pressure to displace the solvent, cooled and stirred for 1 hour to mature the crystals. The crystallized solution was filtered to give wet 1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one crystals (dry weight 127 kg, yield 86.6%). The amount of dimer in the wet crystals was less than 0.1 wt%.