Sulfuric Acid → 3-Azidopyridine

Temperature

5 °C

3-Aminopyridine (18.89 g, 0.20 mol) was added to a warm (55° C.) solution of 36 ml of concentrated sulfuric acid in 210 ml of water. The mixture was stirred for five minutes and was then cooled to 5° C. and a solution of 16.66 g (0.24 mol) of sodium nitrite in 140 ml of water was added dropwise, keeping the temperature below 6° C. The mixture was left to stir for 20 minutes. Urea (2.4 g, 0.04 mol) was added and the mixture was again left to stir at 5° C. for 20 minutes. A solution of 15.60 g (0.24 mol) of sodium azide in 150 ml of water was added, keeping the temperature below 10° C. Nitrogen was immediately evolved. The mixture was stirred at ambient temperature for 1.5 hours after the addition was complete and was then neutralized to pH 6-7 with sodium bicarbonate and extracted with ether. The ether extract was dried over magnesium sulfate and stripped of solvent to yield 21.5 g (89 percent of theory) of dark oil. NMR (CDCl3): δ8.58 (m, 2H) δ7.47 (m, 2H).

1. customthe temperature below 6° C
2. waitThe mixture was left
3. stirringto stir for 20 minutes
4. waitthe mixture was again left
5. stirringto stir at 5° C. for 20 minutes
6. customthe temperature below 10° C
7. stirringThe mixture was stirred at ambient temperature for 1.5 hours
8. additionafter the addition
9. extractionextracted with ether
10. extractionThe ether extract
11. dry with materialwas dried over magnesium sulfate
12. customto yield 21.5 g (89 percent of theory) of dark oil

ORD record

ord-82180533db8d42d393d745f5e3bcf253

Source dataset

uspto-grants-1988_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04775762