Reference of 4887-88-1, A common heterocyclic compound, 4887-88-1, name is 5-Bromo-1H-benzo[d]imidazole, molecular formula is C7H5BrN2, 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.
To a solution of crude, impure 5-bromobenzimidazole (46.2 g) and methyl 2-chloro-3-oxo-2,3-dihydrothiophene-2-carboxylate (Synthesis, 1984, 10, 847-850) (42 g, 220 mmol) in 800 mL of CHCl3 was added N-methylimidazole (28 mL, 345 mmol). After 16 h, N-methylimidazole (17 mL, 220 mmol) and tert-butylchlorodimethylsilane (36 g, 240 mmol) was added. When TLC showed the reaction to be complete, the solution was diluted with water. The layers were separated. The organic phase was washed with water, dried over MgSO4 and concentrated onto celite. The crude mixture was purified by flash column chromatography (0-25% EtOAc:hexanes) in batches to separate the 2 regioisomers, giving 33.5 g of Intermediate 3 eluting first and 29.2 g of Intermediate 4 eluting second (58%). (Intermediate 3, 5-Br) 1H NMR (400 MHz, d6-DMSO) delta 8.77 (s, 1H), 8.01 (d, J=1.6 Hz, 1H), 7.76 (d, J=8.8 Hz, 1H), 7.56 (dd, J=8.8 and 1.6 Hz, 1H), 7.25 (s, 1H), 3.76 (s, 3H), 0.99 (s, 9H), 0.27 (s, 6H). (Intermediate 4, 6-Br) 1H NMR (400 MHz, d6-DMSO) delta 8.71 (s, 1H), 7.88 (d, J=1.6 Hz, 1H), 7.73 (d, J=8.8 Hz, 1H), 7.50 (dd, J=8.8 and 2.0 Hz, 1H), 7.26 (s, 1H), 3.77 (s, 3H), 0.99 (s, 9H), 0.26 (s, 6H).
The synthetic route of 4887-88-1 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Kuntz, Kevin Wayne; Emerson, Holly Kathleen; Cheung, Mui; Badiang, Jennifer Gabriel; US2009/326029; (2009); A1;,
Imidazole – Wikipedia,
Imidazole | C3H4N2 – PubChem