4-Aminophenol → 4-[(3-Nitropyridin-2-yl)amino]phenol

Temperature

50 °C

A mixture of 2-chloro-3-nitropyridine (2C3NP, 138.1 Kg), 4-aminophenol (2.5-3 equivalents) and N,N-dimethylformamide (DMF, 4.8 mL/g 2C3NP) was stirred until homogeneous, heated at 50° C. during which an exotherm raised the solution temperature to 70° C., warmed to 80-85° C., stirred until no 2-chloro-3-nitropyridine remained, cooled to 30° C., treated with water (10.6 mL/g 2C3NP) to precipitate product, then with acetic acid (1.2 mL/g 2C3NP), then with ethyl acetate (0.5 mL/g 2C3NP), cooled to 5° C., stirred for 2 hours and filtered. The filtrant was washed sequentially with distilled water (1.6 mL/g 2C3NP), cold ethanol (1.2 mL/g 2C3NP) and cold isopropyl ether (1.2 mL/g 2C3NP), and dried under vacuum.

1. temperatureraised the solution temperature to 70° C.
2. temperaturewarmed to 80-85° C.
3. temperaturecooled to 30° C.
4. customto precipitate product
5. temperaturewith acetic acid (1.2 mL/g 2C3NP), then with ethyl acetate (0.5 mL/g 2C3NP), cooled to 5° C.
6. stirringstirred for 2 hours
7. filtrationfiltered
8. washThe filtrant was washed sequentially with distilled water (1.6 mL/g 2C3NP), cold ethanol (1.2 mL/g 2C3NP) and cold isopropyl ether (1.2 mL/g 2C3NP)
9. customdried under vacuum

ORD record

ord-05c1d4e743ca4f0a873a74e2039bb808

Source dataset

uspto-grants-2008_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07449584B2