Reaktion #9281

Reaktionsgleichung

7-bromo-2-ethyl-3-nitropyrazolo[1,5-a]pyridine

2-chloro-4-methoxyphenylboric acid

barium hydroxide octahydrate

ethyl acetate

→

title compound

Ausbeute 73.3%

7-(2-Chloro-4-methoxyphenyl)-2-ethyl-3-nitropyrazolo[1,5-a]pyridine

Ausbeute 73.3%

Lösungsmittel

1,2-dimethoxyethane

water

Water

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added
2. 2
   Temperaturthe mixture was heated
3. 3
   Waschenthe extract was washed with saturated aqueous sodium hydrogencarbonate and brine, in that order
4. 4
   TrocknenAfter drying over anhydrous magnesium sulfate and filtration
5. 5
   Einengenthe solvent was concentrated under reduced pressure
6. 6
   Sonstigethe residue was purified by silica gel column chromatography

Vorschrift

After dissolving 7-bromo-2-ethyl-3-nitropyrazolo[1,5-a]pyridine (100 mg) in 1,2-dimethoxyethane (6 mL) and water (1 mL), 2-chloro-4-methoxyphenylboric acid (138 mg), tetrakis(triphenylphosphine)palladium (0) complex (86 mg) and barium hydroxide octahydrate (233 mg) were added and the mixture was heated and stirred at 80° C. for 3 hours under a nitrogen stream. Water was added to the reaction mixture, extraction was performed with ethyl acetate and the extract was washed with saturated aqueous sodium hydrogencarbonate and brine, in that order. After drying over anhydrous magnesium sulfate and filtration, the solvent was concentrated under reduced pressure, the residue was purified by silica gel column chromatography, and the title compound (90 mg) was obtained from the n-hexane:ethyl acetate (30:1) fraction as yellow crystals.

Quelle