Acetic Anhydride → Ethanone, 1-(2,3-dihydro-6-benzofuranyl)- (9CI)

Participants

Reaction Conditions

Reaction Steps

A solution of bromo(2,3-dihydro-1-benzofuran-6-yl)magnesium (prepared from 6-bromo-2,3-dihydro-benzofuran (2.50 g, 12.56 mmol) and Mg (0.336 g, 13.8 mmol)) in THF (10 mL) was dropwise added to a solution of acetic anhydride (2.40 mL, 25.4 mmol) in Et2O (10 mL) held at −78° C. The reaction mixture was stirred at −78° C. for 1 h before the temperature was allowed to reach −10° C. over a period of 1 h. The reaction mixture was quenched by the addition of NH4Cl (aq, saturated, 20 mL) and the resulting mixture was extracted twice with Et2O (2×10 mL). The organic extracts were pooled, washed with NaOH (aq, 5%, 10 mL) and brine (10 mL), dried over MgSO4 and concentrated under reduced pressure. The residue was purified by preparative HPLC using a gradient of 20-50% MeCN in a 0.1M ammonium acetate buffer as eluent. Freeze-drying of the pure fractions gave the desired product.

Provenance & Evidence