Hydrochloric Acid → HCID 178479081, compound

Temperature

70 °C

The solution of 2-acetamidopyridine was chilled in an ice bath to 10°-15° C and treated with 118 g. of commercial 40% peracetic acid which was slowly added over a 40-minute period with ice-cooling and stirring. During the course of the addition the temperature was between 15°-25° C. After 1 hour stirring, with little cooling (temperature 20°-30° C), the turbid solution was heated for 3.5 hours at 70° C with stirring. To the clear hot solution were added 85 g. 37.5% hydrochloric acid and 37 g. water, and to the resulting cloudy solution was added 3.5 g. 37% formaldehyde solution to destroy any unreacted excess of peroxide compounds. The mixture was stirred and heated 2.5 hours at 80°-82° C. After cooling to room temperature, 40 g. xylene was added and the cloudy solution was evaporated, under vacuum, in a rotary evaporator, until the residue was solid. The resulting moist crystals were dried at 50°-60° C under vacuum, to give 116 g. of 2-aminopyridine-1-oxide hydrochloride, which on recrystallization from 1:1 ethanoltoluene mixture, weighed 98.8 g. The resulting colorless crystals gave a m.p. of 155°-156° C.

1. additiontreated with 118 g
2. temperaturecooling
3. additionDuring the course of the addition the temperature
4. customwas between 15°-25° C
5. stirringAfter 1 hour stirring
6. temperaturewith little cooling (temperature 20°-30° C)
7. stirringwith stirring
8. additionTo the clear hot solution were added 85 g
9. custom37% formaldehyde solution to destroy any unreacted excess of peroxide compounds
10. stirringThe mixture was stirred
11. temperatureheated 2.5 hours at 80°-82° C
12. temperatureAfter cooling to room temperature
13. additionxylene was added
14. customthe cloudy solution was evaporated, under vacuum, in a rotary evaporator, until the residue
15. customThe resulting moist crystals were dried at 50°-60° C under vacuum
16. customto give 116 g
17. customof 2-aminopyridine-1-oxide hydrochloride, which on recrystallization from 1:1 ethanoltoluene mixture
18. customThe resulting colorless crystals gave a m.p. of 155°-156° C.

ORD record

ord-83e37178c5d240f0b1c18a4826a2573c

Source dataset

uspto-grants-1978_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04080329