* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
With toluene-4-sulfonic acid In toluene at 60℃; for 24 h; Schlenk technique
4-Chloro-o-phenylenediamine (71. Omg, 0.5 mmol), 3,5-diheptanone (64.0 mg, 0.5 mmol) and Toluenesulfonic acid (9. 5 mg, 0. 05 mmol) was added sequentially to a 25 mL Schlenk flask, toluene (4. OmL) was added, Placed in oil bath 60 ° C reaction 24h. After the end of the reaction, the solvent was removed under reduced pressure, using petroleum ether / ethyl acetate as eluent The yield of 2-ethyl-5-chlorobenzimidazole was 95percent by silica gel column separation.
95%
With sodium iodide dichloride In tetrahydrofuran; waterReflux
General procedure: To a mixture of o-substituted (–NH2 or –SH or –OH) anilines(1.0 mmol) and appropriate 1,3-diketones (1.1 mmol) in THF(5 mL) was added 30percentw/w aqueous NaICl2 (0.2 mmol, 20molpercent). The reaction was allowed to remain stirred at refluxtemperature for 2–3 h. After the reaction was complete, asindicated by TLC, the mixture was cooled to room temperature.The volatiles were removed under reduced pressureand treated successively with aqueous sodium thiosulphatesolution and saturated solution of NaHCO3, and extractedby ethylacetate (2×10 mL). The combined organic phaseswere washed with brine and dried over Na2SO4 and evaporatedunder vacuum. The crude reaction mixture was purifiedby column chromatography on silica gel using petroleumether/ethyl acetate as eluents.
Reference：
[1] Organic Letters, 2014, vol. 16, # 3, p. 764 - 767
[2] Patent: CN103910682, 2016, B, . Location in patent: Paragraph 0035-0037
[3] Journal of Chemical Sciences, 2018, vol. 130, # 1,
2
[ 1537095-91-2 ]
[ 34569-15-8 ]
Yield
Reaction Conditions
Operation in experiment
90.2%
With tin(II) chloride dihdyrate In ethanol at 25℃; for 2 h;
General procedure: A solution of 2-nitro-5-substitutedaniline (1 mmol), difference substituted N,N-dimethylamine(1.5 mmol) and phosphorus oxychloride (2.5 mL) in toluene(10 mL) was refluxed for 4 h at 120 8C. The mixture was cooledand poured onto crushed ice, then made basic with sodiumbicarbonate solution. The organic layer was washed with water,then dried over sodium sulfate and evaporated under vacuo. Thecrude material was purified by chromatography on silica gelcolumn using ethyl acetate and petroleum ether (1:1 by volume)as the eluent. The solvent was removed under reduced pressure toafford the different substituted N,N-dimethyl-N0-(2-nitrophenyl)imidamide intermediates (2). Next, a mixture of 2 (1 mmol) andstannous chloride dihydrate (4 mmol) in ethanol (10 mL) wasstirred at room temperature for 1 h. The solvent was removedunder vacuo and the mixture was dissolved in dichloromethaneand washed with sodium bicarbonate solution. The organic layerwas then dried over sodium sulfate and evaporated in vacuo. Thecrude material was purified by chromatography on silica gelcolumn using ethyl acetate and petroleum ether (1:2 by volume) aseluent. The solvent was removed under reduced pressure to give2,5-disubstitued benzimidazoles 3.
Reference：
[1] Chinese Chemical Letters, 2014, vol. 25, # 1, p. 155 - 158
3
[ 95-83-0 ]
[ 115-80-0 ]
[ 34569-15-8 ]
Reference：
[1] Journal of Heterocyclic Chemistry, 2007, vol. 44, # 6, p. 1509 - 1512
[2] European Journal of Organic Chemistry, 2011, # 15, p. 2827 - 2835
[3] Journal of Chemical Research - Part S, 2000, # 12, p. 584 - 585
With tin(II) chloride dihdyrate; In ethanol; at 25℃; for 2.0h;
General procedure: A solution of 2-nitro-5-substitutedaniline (1 mmol), difference substituted N,N-dimethylamine(1.5 mmol) and phosphorus oxychloride (2.5 mL) in toluene(10 mL) was refluxed for 4 h at 120 8C. The mixture was cooledand poured onto crushed ice, then made basic with sodiumbicarbonate solution. The organic layer was washed with water,then dried over sodium sulfate and evaporated under vacuo. Thecrude material was purified by chromatography on silica gelcolumn using ethyl acetate and petroleum ether (1:1 by volume)as the eluent. The solvent was removed under reduced pressure toafford the different substituted N,N-dimethyl-N0-(2-nitrophenyl)imidamide intermediates (2). Next, a mixture of 2 (1 mmol) andstannous chloride dihydrate (4 mmol) in ethanol (10 mL) wasstirred at room temperature for 1 h. The solvent was removedunder vacuo and the mixture was dissolved in dichloromethaneand washed with sodium bicarbonate solution. The organic layerwas then dried over sodium sulfate and evaporated in vacuo. Thecrude material was purified by chromatography on silica gelcolumn using ethyl acetate and petroleum ether (1:2 by volume) aseluent. The solvent was removed under reduced pressure to give2,5-disubstitued benzimidazoles 3.
With toluene-4-sulfonic acid; In toluene; at 60℃; for 24.0h;Schlenk technique;
4-Chloro-o-phenylenediamine (71. Omg, 0.5 mmol), 3,5-diheptanone (64.0 mg, 0.5 mmol) and Toluenesulfonic acid (9. 5 mg, 0. 05 mmol) was added sequentially to a 25 mL Schlenk flask, toluene (4. OmL) was added, Placed in oil bath 60 ° C reaction 24h. After the end of the reaction, the solvent was removed under reduced pressure, using petroleum ether / ethyl acetate as eluent The yield of 2-ethyl-5-chlorobenzimidazole was 95percent by silica gel column separation.
95%
With sodium iodide dichloride; In tetrahydrofuran; water;Reflux;
General procedure: To a mixture of o-substituted (?NH2 or ?SH or ?OH) anilines(1.0 mmol) and appropriate 1,3-diketones (1.1 mmol) in THF(5 mL) was added 30percentw/w aqueous NaICl2 (0.2 mmol, 20molpercent). The reaction was allowed to remain stirred at refluxtemperature for 2?3 h. After the reaction was complete, asindicated by TLC, the mixture was cooled to room temperature.The volatiles were removed under reduced pressureand treated successively with aqueous sodium thiosulphatesolution and saturated solution of NaHCO3, and extractedby ethylacetate (2×10 mL). The combined organic phaseswere washed with brine and dried over Na2SO4 and evaporatedunder vacuum. The crude reaction mixture was purifiedby column chromatography on silica gel using petroleumether/ethyl acetate as eluents.
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
Life Science
For Research Only
100K+ Compounds
Competitive Price
1-2 Day Shipping
