Nitric Acid → 2,6-Difluoro-3-nitropyridine

Temperature

35 °C

To a stirred solution of 20 g. of 2,6-difluoropyridine in 100 ml. of concentrated sulfuric acid at about 20° C., was added 75 ml. of 90% fuming nitric acid over 20 minutes. The mixture was kept at room temperature overnight, warmed to 35° C. over 15 minutes and held at this temperature for 10 minutes. The solution was cooled and poured into ice. The oil was extracted with 400 ml. of ether and the ether extract was washed with bicarbonate solution until all of the acid was neutralized. The ether was dried, evaporated and the residue was distilled at 0.1 mm. The only fraction came over at 50° C.

1. waitheld at this temperature for 10 minutes
2. temperatureThe solution was cooled
3. additionpoured into ice
4. extractionThe oil was extracted with 400 ml
5. extractionof ether and the ether extract
6. washwas washed with bicarbonate solution until all of the acid
7. dry with materialThe ether was dried
8. customevaporated
9. distillationthe residue was distilled at 0.1 mm
10. customcame over at 50° C.

ORD record

ord-14705389431646d182691c98200e87b7

Source dataset

uspto-grants-1979_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04144341