Chlorodifluoromethane → 4-(Difluoromethoxy)-3-hydroxybenzaldehyde

To a well stirred suspension of 3,4-dihydroxy benzaldehyde (100 gm) and anhydrous potassium carbonate (120 gm) in dry N,N-dimethylformamide (1.0 lit) was passed chlorodifluoromethane gas for about 30 minutes at about 80-85° C. After an hour another lot of anhydrous potassium carbonate (25.0 gm) was added and stirred for about one and half hours. The third lot of anhydrous potassium carbonate (25.0 gm) was added and stirred for about one and half hours. The reaction mixture was then stirred for about 5-6 hours at an ambient temperature. The reaction mixture was filtered and the filtrate was concentrated under reduced pressure. The residue obtained was diluted with water (500 mL) and extracted with ethyl acetate (3×200 mL). The combined organic layer was dried over anhydrous sodium sulphate and concentrated under reduced pressure. The crude product obtained was purified through silica gel column to give 4-difluoromethoxy-3-hydroxy benzaldehyde.

1. customfor about 30 minutes
2. customat about 80-85° C
3. stirringstirred for about one and half hours
4. stirringstirred for about one and half hours
5. stirringThe reaction mixture was then stirred for about 5-6 hours at an ambient temperature
6. filtrationThe reaction mixture was filtered
7. concentrationthe filtrate was concentrated under reduced pressure
8. customThe residue obtained
9. extractionextracted with ethyl acetate (3×200 mL)
10. dry with materialThe combined organic layer was dried over anhydrous sodium sulphate
11. concentrationconcentrated under reduced pressure
12. customThe crude product obtained
13. customwas purified through silica gel column

ORD-Eintrag

ord-ac21ed1fc5ba469eb3bf2c9a44f79dad

Quelldatensatz

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US08524905B2