Hydrochloric Acid → 2-Chloro-5-nitrophenol

Temperature

80 °C

A saturated solution of sodium nitrite (1.8 g, 26.0 mmol) in water (12 mL) was added dropwise to a suspension of 2-amino-5-nitro-phenol (2.0 g, 13.0 mmol) in concentrated hydrochloric acid (10 mL) at 0° C. and stirred for 30 min. In another flask, copper (I) chloride (5.15 g, 52.0 mmol) and concentrated hydrochloric acid (20 mL) were heated to between 60 and 70° C. and the diazonium salt solution was added dropwise to this over a period of 30 min. The reaction mixture was heated to 80° C. and stirred for 15 min. It was then cooled to room temperature and ethyl acetate (50 mL) was added and stirred for 5 min. The organic phase was separated and the aqueous phase was extracted with ethyl acetate (2×50 mL). The combined organic phases were washed with water (4×50 mL), brine, dried over anhydrous sodium sulfate and concentrated in vacuo to give a residue which was purified by column chromatography over silica gel (100-200 mesh) using 5% ethyl acetate in petroleum ether as eluent to afford 2-chloro-5-nitro-phenol (2.08 g, 92%) as a crystalline yellow solid.

1. stirringstirred for 15 min
2. temperatureIt was then cooled to room temperature
3. stirringstirred for 5 min
4. customThe organic phase was separated
5. extractionthe aqueous phase was extracted with ethyl acetate (2×50 mL)
6. washThe combined organic phases were washed with water (4×50 mL), brine
7. dry with materialdried over anhydrous sodium sulfate
8. concentrationconcentrated in vacuo
9. customto give a residue which
10. customwas purified by column chromatography over silica gel (100-200 mesh)

ORD record

ord-d638fc1dd9e949e4bf025e357cbd4d69

Source dataset

uspto-grants-2013_09

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08524705B2