Dimethyl Sulfoxide → 12H-dibenzo[d,g][1,3]dioxocin-12-one

A mixture of 21.4 g (100 mmol) of 2,2'-dihydroxybenzophenone, 150 mL of anhydrous dimethyl sulfoxide, 20.9 g (120 mmol) of dibromomethane, and 30.4 g of dry powdered potassium carbonate was prepared and was heated by means of an oil bath set at 75° C. and stirred. The temperature rose to 87° C. over a 15-min period and then dropped. After another 1.5 hours, the mixture was cooled, diluted with 250 mL of water and 100 mL of 1N aqueous sodium hydroxide. This mixture was extracted with ether (2×100 mL) and the combined ether extracts were washed with water (2×100 mL), dried over sodium sulfate, and concentrated by evaporation under reduced pressure to obtain 19.4 g of a light yellow, mostly solid residue. The residue was recrystallized from 50 mL of a 1:1 benzene/hexane mixture and washed with hexane to obtain, after drying at 75° C. under reduced pressure, 12.4 g (71 percent of theory) of the title compound as a white solid melting at 92.5°-94° C.

1. customwas prepared
2. temperaturewas heated by means of an oil bath
3. customset at 75° C.
4. waitThe temperature rose to 87° C. over a 15-min period
5. additiondropped
6. temperaturethe mixture was cooled
7. extractionThis mixture was extracted with ether (2×100 mL)
8. washthe combined ether extracts were washed with water (2×100 mL)
9. dry with materialdried over sodium sulfate
10. concentrationconcentrated by evaporation under reduced pressure
11. customto obtain 19.4 g of a light yellow, mostly solid residue
12. customThe residue was recrystallized from 50 mL of a 1:1 benzene/hexane mixture
13. washwashed with hexane
14. customto obtain
15. dry with materialafter drying at 75° C. under reduced pressure, 12.4 g (71 percent of theory) of the title compound as a white solid melting at 92.5°-94° C.

ORD record

ord-ae1e21f93ee94b3da1b31082a39bee0c

Source dataset

uspto-grants-1998_07

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05780465