3-Fluoro-4-nitrobenzaldehyde → (E)-3-(3-Fluoro-4-nitro-phenyl)-acrylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

To a suspension of (tert-butoxycarbonylmethyl)triphenylphosphonium chloride (1.6 g, 3.9 mmol; [35000-37-4]) in tetrahydrofuran (10 ml) was added potassium tert-butoxide (0.44 g, 3.9 mmol). After stirring for 15 min 3-fluoro-4-nitrobenzaldehyde (0.60 g, 3.5 mmol; [160538-51-2]) was added. After 1.5 h the suspension was poured on water, the phases were separated and the aqueous phase extracted three times with ethyl acetate. The combined organic layers were washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by flash-chromatography using a gradient of n-heptane:tert-butyl methyl ether (100:0 to 80:20) to give the title compound (804 mg, 3.01 mmol; 86%) as light brown solid. MS: m/e=194.0 [M−C4H9O+].

Herkunft & Nachweise