Hydrochloric Acid → 2-Amino-6-nitrophenol

Ref.: WO 96/11917. A slurry of 2,6-dinitro phenol (20% in H2O, 5 g, 0.0271 mol), NH4Cl (14.30 g, 0.267 mol), and ammonium hydroxide solution (3 mL) was heated in a 70° C. bath. A warm solution of Na2S-9H2O (24.19 g, 0.1 mol) in H2O (23 mL) was added to the slurry and the resulting orange suspension was heated with stirring for 3 h, then allowed to cool to room temperature. The mixture was cooled in an ice bath and slowly acidified with 6 N HCl to pH 2. The mixture was filtered and the filtrate was extracted with CHCl3 (3×75 mL). The combined organic extracts were concentrated in vacuo and the crude material was adsorbed onto silica gel. Purification by silica gel chromatography, eluting with 25% hexane/CH2Cl2 then CH2Cl2, afforded the title compound (1.47 g) as a brick red powder. MS (ESI-POS): [M+H]+=155.

1. temperaturethe resulting orange suspension was heated
2. temperatureThe mixture was cooled in an ice bath
3. filtrationThe mixture was filtered
4. extractionthe filtrate was extracted with CHCl3 (3×75 mL)
5. concentrationThe combined organic extracts were concentrated in vacuo
6. customPurification by silica gel chromatography
7. washeluting with 25% hexane/CH2Cl2

ORD record

ord-babcbedfced6491c863ff3af63fb866a

Source dataset

uspto-grants-2009_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07531542B2