1,2,4-Triazine, 3-bromo-5,6-diphenyl- synthesis

Yield:1292318-80-9 72%

Reaction Conditions:

with N,N-dimethyl-aniline;phosphorus(V) oxybromide in dichloromethane; for 1 h;Reflux;

Steps:

4.2 Synthesis of 3-bromo-5,6-diphenyl-1,2,4-triazine 5b

5,6-Diphenyl-3-hydroxy-1,2,4-triazine (2g, 8.0mmol) was dissolved in dichloromethane (32mL) and solution of phosphorus oxybromide (3.5g, 12.0mmol) in dichloromethane (5mL) was added dropwise followed by addition of N,N-dimethylaniline (1.1mL, 8.8mmol). The reaction mixture was refluxed for 1h, then the solvent was removed by distillation and the residue was poured into iced-water. The formed precipitate was filtered of and the product was purified by silica gel column chromatography using hexanes/EtOAc (5:1) to produce 5b as a yellow solid, yield 72% (1.8g). Mp 154-155°C. ¹H NMR (400MHz, CDCl₃) δ: 7.58-7.32 (m,10H). ¹³C NMR (100MHz, CDCl₃) δ: 158.2, 157.0, 154.9, 134.6, 134.3, 131.9, 130.5, 130.3, 129.7, 129.2, 129.0. Anal. Calcd for C₁₅H₁₀BrN₃ (311.01): C, 57.71; H, 3.23; N, 13.46; found: C, 57.65; H, 3.13; N, 13.46.

References:

Wolińska, Ewa [Tetrahedron,2013,vol. 69,# 35,p. 7269 - 7278]