5-Nitrobenzimidazole synthesis
- Product Name:5-Nitrobenzimidazole
- CAS Number:94-52-0
- Molecular formula:C7H5N3O2
- Molecular Weight:163.13
64-18-6
99-56-9
94-52-0
First, 4-nitrophthalimide (1 g) was mixed with formic acid (0.74 mL) in 5N hydrochloric acid (70 mL), stirred and heated to reflux for 24 hours. Upon completion of the reaction, the mixture was cooled to room temperature, neutralized with 10% sodium hydroxide solution and the precipitate was isolated. Subsequently, the precipitate was recrystallized with water and dried to give 5-nitrobenzimidazole (0.69 g) [37].
Yield:94-52-0 90%
Reaction Conditions:
with mesoporous nanocomposite of Fe3O4 and -NHSO3H functionalized silica (MCM-41) in neat (no solvent) at 90; for 0.333333 h;
Steps:
General procedure for the synthesis of benzimidazole, benzoxazole, andbenzothiazole derivatives 2(a-o)
General procedure: To a mixture of 1,2-phenylenediamine, 2-aminophenol, or 2-aminothiophenol, asappropriate (1 mmol), and the desired ortho ester (trimethyl orthoformate, triethylorthoformate, or triethyl orthoacetate) (1.5 mmol), in neat conditions, Fe3O4MCM-41NH-SO3H (0.03 g) was added and the resulting mixture was stirred in an oil bath at90 C for the proper time as determined by TLC [EtOAc: n-hexane (1:2)]. After endingthe reaction, ethyl acetate (20 mL) was added and the catalyst was separated by an externalmagnet. The organic phase was washed with brine and dried over Na2SO4. After filtration,the solvent was removed from the product under reduced pressure to obtainthe pure product. In some cases, the product was purified by recrystallization from nhexane.The known compounds were identified by matching their IR and NMR datawith literature values from the references cited, as well as melting points for those compoundswhich were solids. For the sake of completeness, the spectral data of some representativecompounds follow.
References:
Pourhasan-Kisomi, Reyhaneh;Shirini, Farhad;Golshekan, Mostafa [Organic Preparations and Procedures International,2021,vol. 53,# 2,p. 166 - 175]
51-17-2
591 suppliers
$14.00/25g
94-52-0
256 suppliers
$8.00/5g
99-56-9
396 suppliers
$6.00/5g
94-52-0
256 suppliers
$8.00/5g