Synthesis
The general procedure for the synthesis of 5-(4-bromophenyl)-1H-tetrazole from 4-bromobenzonitrile was as follows: at 85 °C, a tetrabutylammonium fluoride trihydrate (TABF-3H2O) (1.31 g, 5 mmol), 4-bromobenzonitrile (1.82 g, 10 mmol), and trimethylmethylsilylazide (TMSN3) (1.73 g, 15 mmol) The mixture was reacted under vigorous stirring conditions for 18 hours. After completion of the reaction, the reaction mixture was cooled to room temperature, ethyl acetate (EtOAc) was added and washed with 3 x 150 mL hydrochloric acid (HCl). The organic layer was separated and the remaining aqueous phase was further extracted with ethyl acetate. All organic phases were combined, dried with anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to afford the target product 5-(4-bromophenyl)-1H-tetrazole in 97.2% yield. The melting point of the product was 260-261 °C. 1H NMR (400 MHz, DMSO-d6) data: δ 8.19-7.89 (m, 2H), 7.83 (d, J = 8.6 Hz, 2H). 13C NMR (400 MHz, DMSO-d6) data: δ 132.98 (s), 129.36 (s), 125.20 (s) .
References
[1] Journal of the Brazilian Chemical Society, 2012, vol. 23, # 12, p. 2197 - 2203
[2] Tetrahedron Letters, 2014, vol. 55, # 44, p. 6034 - 6038
[3] Synthetic Communications, 2015, vol. 45, # 8, p. 1023 - 1030
[4] Transition Metal Chemistry, 2017, vol. 42, # 8, p. 703 - 710
[5] Angewandte Chemie - International Edition, 2010, vol. 49, # 39, p. 7101 - 7105
