Nitrogen → 4-Cyano-2-ethoxybenzoic acid

Beteiligte Stoffe

Reaktionsschritte

In a 1 l reactor equipped with a sealed mechanical stirrer, CuCN (12 g, 134 mmol) were suspended in 100 ml of distilled water. NaCN (18.3 g, 373 mmol) was added with vigorous stirring and the internal temperature was kept below 40° C. until all the CuCN went into solution. The suspension of 2-ethoxy-4-aminobenzoic acid (20 g, 110 mmol) in water (200 ml) and concentrated HCl (33 ml) was stirred and cooled in an ice bath. When the temperature reached 5° C., a solution of NaNO2 (9.7 g, 140 mmol) in water (30 ml) was added dropwise at such a rate as to maintain the temperature below 5° C. When all the NaNO was added, the solution was slowly introduced through an ice cooled dropping funnel into the reactor containing the NaCN/CuCN solution. A reaction took place with the vigorous formation of N2. A few drops of octanol were added to keep the foaming under control. Stirring was continued for 4 h. The resulting suspension was then extracted with ethyl acetate (3×100 ml) and the organic phase dried over MgSO4 and evaporated under vacuum obtaining 15 g of the title compound (yield 71.1%) as a light brown powder, mp=170-172° C.

Herkunft & Nachweise