Water → diethyl {(E)-2-[3-(methylamino)-1-phenyl-1H-pyrazol-4-yl]ethenyl}phosphonate

Participants

Reaction Steps

To a solution (5 mL) of tetraethyl methylenediphosphonate in N,N-dimethylformamide was added sodium hydride (60% in oil, 8.8 mg) at room temperature, and the mixture was stirred for 15 min. 3-(Methylamino)-1-phenyl-1H-pyrazole-4-carbaldehyde (1.00 g) was added to the reaction mixture, and the mixture was further stirred at room temperature for 2 hrs. Water was added to the reaction mixture and the mixture was stirred at room temperature for 2 hrs, and stood still for 16 hrs. The precipitated pale-yellow needle crystals were collected by filtration. The obtained crystals were recrystallized from ethyl acetate-hexane to give diethyl {(E)-2-[3-(methylamino)-1-phenyl-1H-pyrazol-4-yl]ethenyl}phosphonate as pale-yellow needle crystals (1.45 g, yield 87%). melting point: 132-133° C.

Provenance & Evidence