反应详情

4,5-Dibromo-1,2,6,7-tetrahydro-8H-indeno[5,4-b]furan-8-one (280 kg, 843 mol), anhydrous sodium acetate (173 kg, 2109 mol), methanol (6384 L) were mixed, and the reaction system was replaced with nitrogen. Then, to the reaction mixture was added 10% Pd/C (30.8 kg, as dry weight), and pressurized with hydrogen to 0.29 to 0.49 MPa, and catalytically reduced at about 40° C. for 8 hrs with stirring at such a stirring rate that the gas-liquid overall mass transfer coefficient KLa(1/hr) is about 15. The catalyst was filtered, and the filtrate was concentrated under reduced pressure, and further water was added to the residue, followed by concentrating under reduced pressure to substitute the solvent, cooling and stirring for 1 hr to mature. The crystallization solution was filtered to give wet crystals of title compound (amount 127 kg as dry weight, yield 86.6%). The content of dimer in the wet crystals was less than 0.1% by weight. (2) Purification Step

1. filtrationThe catalyst was filtered
2. concentrationthe filtrate was concentrated under reduced pressure, and further water
3. additionwas added to the residue
4. concentrationby concentrating under reduced pressure
5. temperaturecooling
6. stirringstirring for 1 hr
7. filtrationThe crystallization solution was filtered