Tetrahydrofuran → HCID 53924800, compound

Temperature

-78 °C

5-Bromo-4-trifluoromethyl-2-pyridone (25 g) was added portionwise to a suspension of sodium hydride (5.5 g of a 50% suspension in mineral oil) in tetrahydrofuran (250 ml) whereupon hydrogen was evolved. The reaction mixture was cooled to -78° C. and a solution (90 ml) of tertiary-butyl lithium (2.6M) in pentane added whilst maintaining the temperature below -55° C. A solution of dry dimethylformamide (40 ml) in tetrahydrofuran (150 ml) at a temperature of -78° C. was added and a thick grey/purple mixture formed. A small amount (ca: 5 mls) ammonium chloride solution was then added and the mixture allowed to warm to room temperature. The resulent yellow solution was partitioned between ammonium chloride (50 ml) and ethylacetate and the ethylacetate extracts were discarded. The aqueous layer was acidified to pH6 using concentrated hydrochloric acid and extracted into ethyl acetate which was washed and dried as described above. The ethyl acetate was then removed under reduced pressure and the resultant brown solid was recrystallised from ethyl acetate to give 5 formyl-4-trifluoromethyl-2-pyridone (13.3 g).

1. temperaturewhilst maintaining the temperature below -55° C
2. customa thick grey/purple mixture formed
3. temperatureto warm to room temperature
4. customThe resulent yellow solution was partitioned between ammonium chloride (50 ml) and ethylacetate
5. extractionextracted into ethyl acetate which
6. washwas washed
7. customdried
8. customThe ethyl acetate was then removed under reduced pressure
9. customthe resultant brown solid was recrystallised from ethyl acetate

ORD record

ord-e7bf28598d064f46bad39bd167266297

Source dataset

uspto-grants-1991_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05039807