Synthetic Route of 15294-81-2, These common heterocyclic compound, 15294-81-2, name is 4,5-Dibromo-1H-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.
Intermediate 14e (0554) 4,5-Dibromo-2-methyl-2H-l,2,3-triazole Batch 1 : To a solution of 4,5-dibromo-lH-triazole (Intermediate 14f; 490.00 g, 2.16 mol) in DMF (3.2 L) was added potassium carbonate (358.23 g, 2.59 mol). The mixture was cooled to -10C under a nitrogen atmosphere and iodomethane (147.91 mL, 2.38 mol) was added dropwise. The reaction was then stirred at 25C for 16 hours. Batch 2: To a solution of 4,5-dibromo-lH-triazole (Intermediate 14f; 400 g, 1.76 mol, 1.00 eq) in DMF (2.8 L) was added potassium carbonate (291.9 g, 2.11 mol). The mixture was cooled to – 10C under a nitrogen atmosphere and iodomethane (131.48 mL, 2.11 mol) was added dropwise. The reaction was then stirred at 25C for 16 hours. Batches 1 and 2 were then combined and the reaction was quenched by the addition of water (4.2 L) and the aqueous phase extracted with MTBE (7 L x 3). The organic extract was concentrated under vacuum to approximately 700 mL and isopropanol (2 L) was added dropwise. This mixture was then stirred at 25 C for 2 hours and the resulting precipitate filtered and dried under vacuum to afford undesired 4,5-dibromo-l-methyltriazole (220 g, 23.5%) as a solid which showed the following NMR spectral data: FontWeight=”Bold” FontSize=”10″ H NMR (400MHz, CDCb) delta 4.09 (s, 3H). 13CNMR (400MHz, CDCb) delta 123.03, 113.09, 37.00. The filtrate was concentrated under vacuum to afford an oil, isopropanol (1 L) was added and resulting solution was warmed to 50 C and then water (3 L) was added dropwise. The mixture was cooled to 25C and stirred for 5 hours and the resulting precipitate was collected by filtration, washed with water (300 mL x 2) and, dried under vacuum at 50C for 16 hours to afford 4,5-dibromo-2- methyl-2H-l,2,3-triazole (Intermediate 14e; 570 g, 60.8% yield) as a solid. FontWeight=”Bold” FontSize=”10″ H NMR (400MHz, CDCb) delta 4.18 (s, 3H). 13C NMR (400MHz, CDCb) delta 124.25, 43.07.
The synthetic route of 15294-81-2 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