4-Nitrobenzaldehyde → 1,2-Bis(4-nitrophenyl)ethanone

Participants

Reaction Steps

A solution of KOH (7.56 g, 0.13 mol) in MeOH (75 ml) was added to the phosphonate ester 33 (62.1 g, 0.13 mol) in THF (400 ml) at -78° C. for 0.5 hour and p-nitrobenzaldehyde (20.3 g, 0.13 mol) in 200 ml of THF was added over 0.5 hour. The reaction was warmed to room temperature and stirred an additional 2 hours. THF was removed under reduced pressure. The residue was taken up in EtOAc and washed twice with 5% aqueous NaHCO3 and once with brine. The ethyl acetate was removed under reduced pressure. The dark red enemine was dissolved in CH3OH (600 ml) and concentrated HCl (0.2 ml) was added. The solution was stirred for 1 hour at room temperature and diluted with H2O (500 ml). The solid was filtered, washed with ether and dried to afford 34 (35.6 g, 82.0%), m.p. 131°-133° C.

Provenance & Evidence