Hydrochloric Acid → Ethyl 2-{[4-(2-methoxyethoxy)-2-nitrophenyl]hydrazono}propanoate

Temperature

7.5 °C

To a mixture of 4-(2-methoxyethoxy)-2-nitroaniline (15.0 g), 6N hydrochloric acid (59 mL) and acetonitrile (50 mL) was added dropwise an aqueous solution (50 mL) of sodium nitrite (4.88 g) at 5-10° C. The reaction mixture was stirred at 5-10° C. for 1.5 hr. This mixture was added to a mixture of ethyl 2-methylacetoacetate (11.2 g), 85% potassium hydroxide (23.8 g), ethanol (50 mL) and water (50 mL) at 10-20° C. The reaction mixture was stirred at 10° C. for 10 min, water was added to the reaction mixture, and the mixture was extracted with ethyl acetate. The ethyl acetate layer was washed with saturated brine, dried (MgSO4), and concentrated. The obtained residue was subjected to silica gel column chromatography, and eluted with hexane-ethyl acetate (4:1-2:1, volume ratio) to give the title compound (1.39 g, yield 6%) as orange crystals.

1. stirringThe reaction mixture was stirred at 10° C. for 10 min
2. extractionthe mixture was extracted with ethyl acetate
3. washThe ethyl acetate layer was washed with saturated brine
4. dry with materialdried (MgSO4)
5. concentrationconcentrated
6. washeluted with hexane-ethyl acetate (4:1-2:1, volume ratio)

ORD record

ord-a183c72b4d5e4d1fb72e4e052539fbec

Source dataset

uspto-grants-2010_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07718798B2