Sodium Azide → 2-Fluoro-3-methoxybenzoyl azide

Participants

Reaction Steps

2-Fluoro-1-isocyanato-3-methoxybenzene. 2-Fluoro-3-methoxybenzoic acid (0.61 g, 3.59 mmol) was dissolved in CH2Cl2 (10 mL) and DMF (0.5 mL). Oxalyl chloride (0.41 mL, 4.7 mmol) was added slowly. The mixture was stirred at rt for 15 min. The mixture was then concentrated and then reconstituted in dioxane (10 mL). Sodium azide (0.26 g, 4.0 mmol) in water/dioxane (1:1 v/v, 10 mL) was added to the acid chloride at 0° C. The mixture was allowed to warm to rt over 1 h. The reaction was then diluted with EtOAc (50 mL) and water (50 mL). The mixture was shaken and separated. The organic layer was dried, filtered, and concentrated. The crude acyl azide was filtered through a silica gel plug (90% Hex in EtOAc). The filtrate was concentrated to afford the intermediate 2-fluoro-3-methoxybenzoyl azide. 2-Fluoro-3-methoxybenzoyl azide was dissolved in toluene (50 mL) and stirred at 100° C. for 1 h. The mixture was concentrated to afford the title compound in quantitative yield.

Provenance & Evidence