Tetrahydrofuran → HCID 69206973, compound

Participants

Reaction Conditions

Reaction Steps

Potassium bis(trimethylsilyl)amide (20% toluene solution, 1.0 g) was added to a mixture of bis(2,2,2-trifluoroethyl) (methoxycarbonylmethyl) phosphonate (318 mg), 18-crown-6 (1.32 g) and tetrahydrofuran (20 mL) at −78° C. Then 5-(4-methoxyphenyl)-1-methyl-1H-pyrazole-4-carbaldehyde (216 mg) was added and the mixture was stirred at −78° C. for 4 hrs. Aqueous ammonium chloride was added to the reaction mixture and the mixture was extracted with ethyl acetate. The organic layer was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated. Methanol (5 mL) and a 1N aqueous sodium hydroxide solution (5 mL) were added to the residue and the mixture was stirred at 60° C. for 1 hr. The reaction mixture was concentrated, 1N hydrochloric acid was added to the residue and the mixture was extracted with ethyl acetate. The organic layer was washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and concentrated. Recrystallization of the residue from ethyl acetate-hexane gave (2Z)-3-[5-(4-methoxyphenyl)-1-methyl-1H-pyrazol-4-yl]acrylic acid as crystals (77 mg, yield 30%). melting point: 205-206° C.

Provenance & Evidence