The solution of the corresponding 2-aminobenzoic acid (15.3 mmol) in water (15 mL)
and conc. HCl (17 mL) was placed in a 200 mL beaker and cooled to 5 °C. To this
mixture a precooled solution of sodium nitrite (1.06 g, 15.3 mmol in 10 mL water) was
added drop wise with vigorous stirring. After stirring for 15 min, a solution of sodium
azide (1.08 g, 16.6 mmol) in 10 mL water was added and the resulting mixture was
gradually warmed to room temperature and stirred at this temperature for about 2 h.
The white crystalline azides precipitated from the reaction mixture and were filtered
off. After washing with cold water and drying in the dark at room temperature the
azides were recrystallized from heptane/benzene (v/v, 1:1). 1H NMR (400 MHz, CDCl3) δ 10.65 (s, 1H), 8.11 (dd, J = 7.9, 1.5 Hz, 1H), 7.66 – 7.56 (m, 1H), 7.31 – 7.21 (m, 2H). 13C NMR (101 MHz, CDCl3) δ 168.8, 140.4, 134.6, 133.4, 125.1, 120.9, 119.7.
