Application of 93-84-5, These common heterocyclic compound, 93-84-5, name is 5-Nitro-1H-benzo[d]imidazol-2(3H)-one, 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.
Step 2) Preparation of 2-Chloro-5-nitro-1H-benzimidazole According to the procedure of A. T. James, et al., J. Chem. Soc., 1515 (1950), a mixture of 2-hydroxy-5-nitro-1H-benzimidazole (10.0 g, 0.0558 mol) and phosphoryl chloride (100 mL) was heated under reflux for 3 hours. The mixture was cooled, concentrated, and ice water was added. The resulting precipitate was collected by filtration. NMR analysis showed the material to be a 1:1 mixture of starting material and product. (Note: Longer heating does not improve the conversion.) Purification by flash chromatography (material preadsorbed onto silica; eluent 40% EtOAc/hexane) gave 4.4 g (40%) of the off-white solid product m.p. 215-217 C. NMR (DMSO-d6, 300 MHz): delta7.68 (d, J=8.9, 1H), 8.12 (dd, J=8.9, 2.3, 1H), 8.39 (d, J=2.3, 1H), 14.00 (brs, 1H).
The synthetic route of 93-84-5 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; American Home Products Corporation; US5149700; (1992); A;,
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