Nitric Acid → HCID 178526837, compound

Temperature

25 °C

To an ice-cooled solution of 3-(trifluoromethyl)pyridin-2-ol (5 g, 30.7 mmol) in H2SO4 (30 mL, 563 mmol) was added nitric acid (1.507 mL, 33.7 mmol) dropwise. After 30 min, the ice bath was removed and the reaction mixture was stirred at 25° C. for 16 h. The reaction mixture was warmed to 60° C. for 5 h, cooled, and added to 150 g of ice. The resulting precipitate was collected by filtration, rinsed with additional H2O, and air-dried to afford the first batch of product. Another crop of product was obtained after evaporating the mother liquor to less than 100 mL, cooling on an ice bath, and adding NaOH to adjust to pH 8. The mixture was extracted by EA (100 mL). The organic layer was dried and concentrated to give the product, which was combined with the first batch to yield a yellow solid of 5-nitro-3-(trifluoromethyl)pyridin-2-ol (5 g, 24.03 mmol, 78.0% yield): 1H NMR (400 MHz, CD3OD) δ 8.85 (d, J=3.2 Hz, 1H), 8.58 (d, J=2.8 Hz, 1H).

1. customthe ice bath was removed
2. temperatureThe reaction mixture was warmed to 60° C. for 5 h
3. temperaturecooled
4. additionadded to 150 g of ice
5. filtrationThe resulting precipitate was collected by filtration
6. washrinsed with additional H2O
7. customair-dried
8. customto afford the first batch of product
9. customAnother crop of product was obtained
10. customafter evaporating the mother liquor to less than 100 mL
11. temperaturecooling on an ice bath
12. additionadding NaOH
13. extractionThe mixture was extracted by EA (100 mL)
14. customThe organic layer was dried
15. concentrationconcentrated
16. customto give the product, which

ORD record

ord-58fbcb5c4e894d0cb8d06e883728868a

Source dataset

uspto-grants-2015_01

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08937071B2