1,1'-Carbonyldiimidazole → 2-amino-N,6-dimethoxybenzamide

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A mixture of 2-amino-6-methoxybenzoic acid (4.6 g, 27.52 mmol) and carbonyl-1,1′-dimidazole (5.35 g, 33.02 mmol) in THF (70 ml) was stirred at 21° C. under nitrogen for 3 days. N,N-diisopropyl-N-ethyl-amine (1.667 ml, 9.57 mmol) and O-methylhydroxylaminehydrochloride (0.545 ml, 7.18 mmol) were added. The solution was heated to 50° C. for 3 hours. After cooling and concentration under vacuum, the reaction mixture was diluted with EtOAc, washed with a saturated aqueous solution of sodium hydrogencarbonate, water and brine, dried over magnesium sulfate, concentrated under vacuum. The residue was purified by flash chromatography on silica gel eluting with 10 to 20% EtOAc in DCM to afford 2-amino-N,6-dimethoxybenzamide (318 mg, 33.9%) as a white solid. Mass spectrum: MH+ 197; NMR Spectrum: (DMSOd6) 3.67 (s, 3H), 3.71 (s, 3H), 5.57 (bs, 2H), 6.19 (d, 1H), 6.31 (d, 1H), 7.02 (dd, 1H)

Herkunft & Nachweise