Lithium Hydroxide → 4-[(Diethoxyphosphorylmethyl)-ethoxyphosphinoyl)-benzoic acid

Participants

Reaction Steps

To a solution of 4-[(Diethoxyphosphorylmethyl)-ethoxyphosphinoyl]-benzoic acid ethyl ester (3c) (1 g, 2.55 mmol) in methanol (25 mL) was slowly added lithium hydroxide (monohydrate, 0.11 g, 2.55 mmol) in water (25 mL). The resulting reaction mixture was stirred at room temperature for 4 hours. The reaction mixture was concentrated to remove methanol and diluted with brine, then extracted with EtOAc (3×100 mL) until the aqueous layer showed little or no evidence of product by HPLC. The combined organics were dried over Na2SO4 and concentrated on rotary evaporator. The desired product (3d) was purified by silica gel flash chromatography as a pale yellow oil (0.91 g). 1H NMR (300 MHz, DMSO-d6) δ(ppm)): 1.13 (m, 9H), 2.94 (t, J=18.2 Hz, 2H), 3.85 (m, 6H), 7.88 (m, 2H), 8.02 (m, 2H), 12.60 (bs, 1H), 31P NMR (121 MHz, DMSO-d6) δ, 37.59 and 24.59

Provenance & Evidence