Ethyl Acetate → Benzyl 3-(2-propionyloxy-5-(ethoxy(diethylphosphonomethyl)phosphinoyl)phenyl)-3-methylbutanoate

Participants

Reaction Steps

Proprionyl chloride (190 μL, 2.17 mmol) was added drop-wise to a stirring solution of crude phenol 122 (880 mg, 1.67 mmol) and DMAP (2 mg, 0.016 mmol) in pyridine (5 mL). The reaction was continued for 3 hr at room temperature followed by the addition of ethyl acetate (100 mL). The organic layer was washed with cold aqueous HCl (0.5 N), H2O and saturated aqueous NaCl then dried over Na2SO4 and concentrated in vacuo. The crude product was purified by silica gel chromatography (0 to 20% methanol in ethyl acetate) using a Biotage Horizons™ system, resulting in 123 as a pale yellow liquid (644 mg, 66%): 1H NMR (400 MHz, CDCl3) δ 1.25 (t, J=7.0, 3H), 1.26 (t, J=7.5, 3H), 1.30 (t, J=7.0, 3H), 1.46 (s, 3H), 1.48 (s, 3H), 2.50-2.63 (m, 4H), 2.82 (AB q, J=14.4, 2H), 3.93-4.16 (m, 6H), 4.93 (s, 2H), 7.12-7.18 (m, 3H), 7.26-7.32 (m, 3H), 7.70 (ddd, J=1.8, 8.4, 11.6, 1H), 7.86 (dd, J=1.8, 13.4, 1H): 31P (162 MHz, CDCl3) δ 20.21 (d, J=9.7, 1 P), 34.03 (d, J=9.7, 1 P).

Provenance & Evidence