Hydrochloric Acid → 5-(5-Bromo-3-pyridyl)-1H-tetrazole

Temperature

100 °C

To the solution of 5-bromo-3-cyanopyridine (3.0 g, 15.9 mmol, 1 eq) in anhydrous dimethylformamide (40 mL) was added ammonium chloride (1.45 g, 1.7 eq) and sodium azide (1.76 g, 1.7 eq). The resulting reaction mixture was heated at 100° C. under nitrogen for 20 hours. After the reaction mixture was cooled to room temperature, it was poured into ice-water and the pH of the mixture was adjusted to ˜3.5 using aqueous hydrochloric acid (2 N). The aqueous was first extracted with ethyl acetate three times, followed by an extraction with i-PrOH—CHCl3 (1:4). All organics were combined and dried with anhydrous sodium sulfate. The upper clear liquor was decanted, concentrated under reduced pressure, and the resulting oily residue was placed under high vacuum for 20 hours. Upon treatment with EtOAc-Hex (1:1) and filtration, 3-bromo-5-(2H-tetrazol-5-yl)pyridine was obtained as a white solid in the amount of 3.241 g.

1. customThe resulting reaction mixture
2. temperatureAfter the reaction mixture was cooled to room temperature
3. extractionThe aqueous was first extracted with ethyl acetate three times
4. extractionfollowed by an extraction with i-PrOH—CHCl3 (1:4)
5. dry with materialdried with anhydrous sodium sulfate
6. customThe upper clear liquor was decanted
7. concentrationconcentrated under reduced pressure
8. filtrationUpon treatment with EtOAc-Hex (1:1) and filtration

ORD record

ord-995ebd45121e4ff2adfd9d4e5826802b

Source dataset

uspto-grants-2016_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US09359336B2