Methyl iodide → 1,5-Dibromo-3-fluoro-2-methoxy-4-methylbenzene

Participants

Reaction Conditions

Reaction Steps

1,5-dibromo-3-fluoro-2-methoxy-4-methylbenzene was prepared from a homogeneous CH3CN (1 L) solution of 4,6-dibromo-2-fluoro-3-methylphenol (˜225.1 g, 792.8 mmol) by adding, at room temperature, K2CO3 (131.5 g, 1.18 mol), followed by MeI (74 mL, 951 mmol). The cloudy solution was stirred at 30° C. and, as monitored by LC, the reaction went to completion at 21 h. The reaction mixture was cooled to room temperature, solid was filtered off by filtration, washing with CH2Cl2 (˜100 mL×2). Filtrate was collected, solvent was removed in in vacuo. Crude product was suspended in CH2Cl2 (200 mL) and the solution was passed through a silica gel pad (˜50 g of silica gel) (note, to remove some darker color baseline impurities and solid initially dissolved in CH3CN), washing with CH2Cl2 (˜100 mL×3). Filtrate was collected, solvent was removed in vacuo. 1,5-dibromo-3-fluoro-2-methoxy-4-methylbenzene was obtained as an off-white solid: 249.46 g (>99% yield); 1H NMR (300 MHz, CDCl3) δ 7.53 (d, J=2.1, 1H), 3.92 (s, 3H), 2.29 (d, J=2.8, 3H).

Provenance & Evidence