Sodium Azide → 1-Fluoro-2-isocyanato-4-methoxybenzene

Beteiligte Stoffe

Reaktionsschritte

(Z)-1-(2-Amino-1,2-dicyanovinyl)-3-(2-fluoro-5-methoxyphenyl)urea. 2-Fluoro-5-methoxybenzoic acid (0.62 g, 3.62 mmol) was dissolved in CH2Cl2 (15 mL) and DMF (0.5 mL). Oxalyl chloride (0.38 mL, 4.32 mmol) was added dropwise. The mixture was stirred for another 15 min. The reaction was concentrated and then taken up in dioxane (10 mL). Sodium azide (0.26 g, 3.96 mmol) in water/dioxane (1:1 v/v, 10 mL) was added to the acid chloride at 0° C. The mixture was stirred for 10 min. The reaction was partitioned between EtOAc and water. The layers were shaken and separated. The organic layer was dried over sodium sulfate, filtered, and concentrated. The crude acyl azide was filtered through a silica gel plug (90% Hexanes in EtOAc. The filtrate was concentrated. The purified acyl azide was dissolved in toluene and stirred at 100° C. for 1 h. The toluene solution was concentrated to afford 1-fluoro-2-isocyanato-4-methoxybenzene in quantitative yield. 1-Fluoro-2-isocyanato-4-methoxybenzene (0.6 g, 3.62 mmol) was reacted with 2,3-diaminomaleonitrile (0.39 g, 3.62 mmol) according to General Procedure A to afford the title compound. MS (ESI) m/z 276.4 [M+1]+.

Herkunft & Nachweise