Chlorodifluoromethane → 1,3-Dibromo-5-(difluoromethoxy)benzene

To a tared, sealed 350 mL round-bottomed pressure flask containing a solution of 3,5-dibromophenol (10.0 g, 39.7 mmol; see Example 27(ii) above) in 2-propanol (100 mL) and 30% KOH (80 mL) at −78° C. was added chlorodifluoromethane via bubbling for 15 min through the septum. The septum was replaced with a Teflon stopper and the flask was then sealed and allowed to warm to room temperature where the flask was weighed and determined to contain 12.0 g (138 mmol) of chlorodifluoromethane. The solution was refluxed overnight in an oil bath set at 80° C. The flask was cooled to room temperature, the pressure cautiously released and the contents diluted with H2O (200 mL). The aqueous layer was extracted with CHCl3 (2× 150 mL), then the combined organics were dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by Kugelrohr distillation at 80° C. at 0.2 mm Hg to afford the sub-title compound (9.6 g, 80%) as clear liquid.

1. customsealed 350 mL round-bottomed pressure flask
2. customvia bubbling for 15 min through the septum
3. customthe flask was then sealed
4. temperatureThe solution was refluxed overnight in an oil bath
5. customset at 80° C
6. temperatureThe flask was cooled to room temperature
7. extractionThe aqueous layer was extracted with CHCl3 (2× 150 mL)
8. dry with materialthe combined organics were dried (Na2SO4)
9. filtrationfiltered
10. concentrationconcentrated in vacuo
11. distillationThe residue was purified by Kugelrohr distillation at 80° C. at 0.2 mm Hg

ORD-Eintrag

ord-843aeb5cdf1546fbba764d48922a7741

Quelldatensatz

uspto-grants-2010_01

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07645751B2