4-(2-fluorobenzyloxy)-N-methyl-N-methoxybenzamide → 1-(4-[2-Fluorobenzyloxy]phenyl)-2-propen-1-one

Participants

Reaction Conditions

Reaction Steps

4-(2-fluorobenzyloxy)-N-methyl-N-methoxybenzamide (P3, 6.0 g, 20.7 mmol) was dissolved in THF (100 mL) and cooled to −78° C. A 1.0 M solution of vinyl magnesium bromide in THF (31 mL, 31 mmol) was added and the cold bath was removed. Upon warming to 20-25° C., the mixture was poured into a vigorously stirred solution of 1 M HCl. The resulting mixture was extracted twice with CH2Cl2. The combined organic layers were then washed with 1 M HCl, then with a saturated NaHCO3 solution, dried over Na2SO4, and concentrated to a thick residue. The product was purified by flash column chromatography eluting with 0→40% acetone hexanes (gradient). Concentration of the fractions containing 4 gave an oil that crystallized upon standing (4.83 g, 91% yield).

Provenance & Evidence