Triethylamine → 6-(Ethoxy(diethylphosphonomethyl)phosphinoyl)-3,4-dihydro-4,4-dimethylchromen-2-one

Participants

Reaction Conditions

Reaction Steps

A mixture of 6-bromo-4,4-dimethylchroman-2-one (3.5 g, 9.7 mmol), diethyl(ethoxyphosphinyl)methylphosphonate (1.7 g, 9.7 mmol), triethylamine (4.1 mL, 29 mmol) and Pd(PPh3)4 (0.56 g, 0.48 mmol) in acetonitrile (20 mL) was heated to 100° C. for 18 hr. The reaction mixture was cooled and diluted with acetonitrile (50 mL) followed by washing with aqueous HCl (10%), water and saturated aqueous NaCl. The organic phase was dried over Na2SO4, filtered and concentrated. The crude product was purified by silica gel chromatography (0-10% methanol in CH2Cl2) on a Biotage™ flash chromatography system, resulting in 120 as pale yellow oil (3.0 g, 73%): 1H NMR (400 MHz, CDCl3) δ 1.21 (t, J=7.2, 3H), 1.30-1.37 (m, 6H), 1.40 (s, 6H), 2.61 (dd, J=1.7, 17.2, 20.7, 2H), 2.66 (s, 2H), 3.95-4.08 (m, 2H), 4.11-4.21 (m, 4H), 7.16 (dd, J=3.1, 8.3, 2H), 7.73 (dd, J=3.1, 8.3, 2H): 31P (162 MHz, CDCl3) δ 20.07 (d, J=7.7, 1 P), 33.74 (d, J=7.7, 1 P).

Provenance & Evidence