Sodium hydride → Ethyl 2-[(4-methoxy-3-nitrophenyl)methylidene]butanoate

Under an argon atmosphere, stirring and cooling with ice, a solution of triethyl 2-phosphonobutyrate (5.00 g, 19.8 mmol) in anhydrous tetrahydrofuran (30 mL) was added dropwise slowly to a solution of sodium hydride (60% oil dispersion, 795 mg, 19.9 mmol) in anhydrous tetrahydrofuran (120 mL). After stirring for 1 hour at 0° C., a solution of 4-methoxy-3-nitrobenzaldehyde (3.26 g, 18.0 mmol) in anhydrous tetrahydrofuran (50 mL) was added dropwise, and the mixture was stirred for 1 hour at 0° C. and for 3 hours at room temperature. The reaction mixture was concentrated and ice water was added to the residue, which was extracted with ethyl acetate. The extracte was washed with water, brine and dried over anhydrous sodium sulfate, and then concentrated. The residue was purified by silica gel column chromatography (eluent n-hexane:ethyl acetate=8:1→2:1 v/v) to obtain 4.69 g (93%) of ethyl 2-ethyl-3-(4-methoxy-3-nitrophenyl)acrylate as colorless crystals.

1. temperaturecooling with ice
2. stirringAfter stirring for 1 hour at 0° C.
3. stirringthe mixture was stirred for 1 hour at 0° C. and for 3 hours at room temperature
4. concentrationThe reaction mixture was concentrated
5. additionice water was added to the residue, which
6. extractionwas extracted with ethyl acetate
7. washThe extracte was washed with water, brine
8. dry with materialdried over anhydrous sodium sulfate
9. concentrationconcentrated
10. customThe residue was purified by silica gel column chromatography (eluent n-hexane:ethyl acetate=8:1→2:1 v/v)

ORD record

ord-f756459d92ab484dbfb79e61503400c4

Source dataset

uspto-grants-2006_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07049342B2