Ethyl 4-bromobenzoate → Ethyl 4-(diethoxyphosphoryl)benzoate

A sealed pressure flask, flushed with N2, containing a mixture of 4-bromo-benzoic acid ethyl ester (2a) (5 g, 0.0218 mol), diethyl phosphite (3.093 mL, 0.024 mol), NMM (2.88 mL, 0.0262 mmol) and Pd(PPh3)4 (2.017 g, 0.00175 mol) in acetonitrile (20 mL) was stirred at ambient temperature for 5–10 min, then heated at 90° C. for 18 hours. The reaction mixture was filtered through celite, and the celite was washed with EtOAc (3×30 mL) until the filtrate showed little or no evidence of product by HPLC. The combined organics were dried over Na2SO4 and concentrated on a rotary evaporator. The desired product was purified by silica gel flash chromatography to give a pale yellow oil (4.24 g). 1H NMR (300 MHz, CDCl3) δ(ppm)) 1.36 (m, 6H), 1.42 (t, J=7 Hz, 3H), 4.16 (m, 4H), 4.42 (q, J=7 Hz, 2H), 7.93 (m, 2H), 8.15 (m, 2H). 31P NMR (121 MHz, CDCl3) δ 17.63.

1. customA sealed pressure flask, flushed with N2
2. additioncontaining
3. temperatureheated at 90° C. for 18 hours
4. filtrationThe reaction mixture was filtered through celite
5. washthe celite was washed with EtOAc (3×30 mL) until the filtrate
6. dry with materialThe combined organics were dried over Na2SO4
7. concentrationconcentrated on a rotary evaporator
8. customThe desired product was purified by silica gel flash chromatography

ORD-Eintrag

ord-3064727042e44329b252a2bcc36b12cb

Quelldatensatz

uspto-grants-2006_11

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07132427B2