Into a 100-mL 3-necked round-bottom flask purged and maintained with an inert atmosphere of nitrogen, was placed a solution of diethyl phosphonate (3.02 g, 21.88 mmol, 1.10 equiv) in toluene (10 mL), Pd(PPh3)4 (1.15 g, 1.00 mmol, 0.05 equiv), TEA (2.21 g, 21.88 mmol, 1.10 equiv), 1-bromo-4-nitrobenzene (4 g, 19.90 mmol, 1.00 equiv). The resulting solution was stirred for 15 h at 90° C. The solids were filtered out and the resulting mixture was concentrated under vacuum. The residue was applied onto a silica gel column and eluted with ethyl acetate/petroleum ether (1:2). This resulted in 3.53 g (68%) of diethyl 4-nitrophenylphosphonate as a yellow liquid.
