4-Nitrobenzaldehyde → HCID 5388588, compound

Participants

Reaction Steps

To a mixture of titanium tetrachloride (20.0 g) and tetrahydrofuran (100 ml) were added 4-nitrobenzaldehyde (8.00 g) and ethyl diethylphosphonoacetate (11.9 g) under ice-cooling, and N-methylmorpholine (21.4 g) was added. The mixture was stirred at room temperature for 1 hr. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was concentrated to give crystals of 4-[(E)-2-(diethylphosphono)-2-ethoxycarbonylethenyl]nitrobenzene (15.7 g, yield 83%), which were recrystallized from dichloromethane-isopropyl ether to give a colorless prism (14.0 g). melting point: 60–61° C. A mixture of this compound (5.00 g), iron (3.13 g), conc. hydrochloric acid (7 ml) and ethanol (30 ml) was stirred at room temperature for 30 min. The reaction mixture was poured into water and the mixture was extracted with ethyl acetate. The ethyl acetate layer was concentrated, and the residue was subjected to silica gel column chromatography to give crystals of 4-[(E)-2-(diethylphosphono)-2-ethoxycarbonylethenyl]aniline (2.40 g, yield 52%) from a fraction eluted with ethyl acetate-hexane (2:1, v/v), which were recrystallized from acetone-isopropyl ether to give a pale yellow needle (1.75 g). melting point: 79–80° C.

Provenance & Evidence