These common heterocyclic compound, 28938-17-2, name is 4,5-Dibromo-2-methyl-2H-1,2,3-triazole, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc, below Introduce a new synthetic route. HPLC of Formula: C3H3Br2N3
Intermediate 14d (0551) 5-Bromo-2-methyl-2H- 1 ,2,3-triazole-4-carboxylic acid (0552) A solution of 4,5-dibromo-2-methyl-2H-l,2,3-triazole (Intermediate 14e; 144 g, 597.81 mmol) in anhydrous THF (1.5 L) was cooled to -30 C under nitrogen atmosphere and i- PrMgCl (330 mL, 658 mmol, 2M in THF) was added dropwise. The solution was stirred at -30 C for 1 hour, and then bubbled with C02 for 3 hours at <10 C. The reaction was then stirred at 25 C for 16 hours. The mixture was quenched with aqueous HC1 (-3000 mL, 0.1M) to pH = ~2 and extracted with EtOAc (3 L x 3). The organic phase was then extracted with aqueous NaOH (0.1M, 2 L x 3). The aqueous phase was then added to aqueous HC1 (~6 L, 0.1M) to pH=~2 and extracted with EtOAc (3L x 3). The organic phase was dried with Na2S04 and concentrated under vacuum to give 5-bromo-2-methyl- 2H-l,2,3-triazole-4-carboxylic acid (Intermediate 14d; 105 g, 85.26% yield) as a white solid. lH NMR (DMSO, 400 MHz) delta 4.23 (s, 3H). 13C-NMR (400MHz, DMSO) delta 160.86, 138.23, 124.52, 43.38.
The synthetic route of 4,5-Dibromo-2-methyl-2H-1,2,3-triazole has been constantly updated, and we look forward to future research findings.
Reference:
Patent; ASTRAZENECA AB; WARD, Richard, Andrew; JONES, Clifford, David; FERON, James, Lyman; (80 pag.)WO2017/80980; (2017); A1;,
1,2,3-Triazole – Wikipedia,
Triazoles – an overview | ScienceDirect Topics