1H-Benzimidazole-4-carboxylic acid synthesis
- Product Name:1H-Benzimidazole-4-carboxylic acid
- CAS Number:46006-36-4
- Molecular formula:C8H6N2O2
- Molecular Weight:162.15
64-18-6
603-81-6
46006-36-4
To a 4M hydrochloric acid (20 mL) solution of formic acid (0.75 mL, 20.0 mmol) was added 2,3-diaminobenzoic acid (1.00 g, 6.6 mmol). The reaction mixture was heated at reflux temperature for 2 h and subsequently cooled to room temperature. The resulting pink precipitate was separated by filtration and dissolved in hot methanol. Decolorization was carried out by adding activated carbon and stirring for 10 min. The suspension was filtered and the solvent was evaporated under reduced pressure to afford benzimidazole-7-carboxylic acid (0.542 g, 51% yield) as white crystals with a melting point of 266-268 °C. The structure of the product was analyzed by 1H NMR (300 MHz, DMSO-d6) δ 9.64 (s, 1H), 8.11 (dd, J = 8.2, 0.9 Hz, 1H), 8.07 (dd, J = 7.6, 0.9 Hz, 1H), 7.65 (dd, J = 8.2, 7.6 Hz, 1H) and 13C NMR (75 MHz, DMSO-d6 ) δ 265.2, 142.0, 132.3, 129.3, 127.6, 125.6, 119.7, 117.6 confirmed.
122-51-0
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46006-36-4
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Yield: 98%
Reaction Conditions:
at 130;
Steps:
5.1.92.A
A. lH-Benzo[d]imidazole-4-carboxyIic acid.; 2,3-Diaminobenzoic acid (1.0 g, 6.57 mmol) was suspended in triethylorthoformate (20 mL) and heated to 130 0C overnight. Diethyl ether (100 mL) was then added and the resulting precipitate filtered to give a white solid (1.04 g, 6.41 mmol, 98%). 1H NMR (400 MHz, DMSO-rf6) δ 8.22 (s, IH), 7.91 (dd, J = S.0, 1.2, IH), 7.82 (dd, J = 8.0, 1.2, IH), 7.29 (dd, J = 8.0, 7.6, IH); MS (ESI) m/z 163.0 [M+ 1]+.
References:
SIGNAL PHARMACEUTICALS, LLC WO2008/51494, 2008, A1 Location in patent:Page/Page column 132
64-18-6
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603-81-6
195 suppliers
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46006-36-4
152 suppliers
$19.00/250mg
64-18-6
1127 suppliers
$22.12/250ML
46006-36-4
152 suppliers
$19.00/250mg
603-81-6
195 suppliers
$7.00/250mg
208772-23-0
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46006-36-4
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46006-36-4
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$19.00/250mg