Nitric Acid → HCID 53754201, compound

HRID 1599467Notes

Reaction equation

HRID 1599467 reaction equation
[N+:1]([O-:4])(O)=[O:2].[N:5]1[C:9]2[CH:10]=[CH:11][CH:12]=[CH:13][C:8]=2[NH:7][C:6]=1[CH2:14][C:15]([O:17][CH2:18][CH3:19])=[O:16].C(=O)([O-])[O-].[Na+].[Na+]>>[N+:1]([C:11]1[CH:12]=[CH:13][C:8]2[N:7]=[C:6]([CH2:14][C:15]([O:17][CH2:18][CH3:19])=[O:16])[NH:5][C:9]=2[CH:10]=1)([O-:4])=[O:2]

Participants

4

Reactant 3

HCID 944Nitric AcidHCID 10340Sodium CarbonateHCID 308071ethyl 2-(1H-1,3-benzodiazol-2-yl)acetate

Product 1

HCID 53754201HCID 53754201, compoundYield 92%

Conditions

Temperature
0 °C

Procedure

Concentrated nitric acid (5 mL) was added to concentrated sulfonic acid (5 mL) at 0° C., and the solution was cooled thoroughly for an additional 10-15 minutes. Ethyl benzimidazole-2-acetate (Buchi, J.; Zwicky, H.; Aebi, A., Archiv. Der Pharmazie 1960, 293, 758; 1.09 g, 5.34 mmol, 1 equiv.) was added portionwise over several minutes The resulting yellow solution was stirred at 0° C. for 20 minutes then was poured carefully onto cracked ice (100 g). The pH was adjusted to 5 with cold 20% sodium carbonate (50-75 mL) and the mixture was extracted with ethyl acetate (3×50 mL). Drying (sodium sulfate), concentration, and silica gel chromatography (3:2 ethyl acetate/toluene) gave ethyl 5-nitrobenzimidazole-2-acetate (1.23 g, 92%) as a yellow solid. TLC (3:2 ethyl acetate/toluene) Rf 0.44; 1H NMR (400 MHz, CDCl3) δ 8.54 (br s, 1H), 8.21 (dd, J=8.9, 2.1 Hz, 1H), 7.58-7.70 (m, 1H), 4.31 (q, J=7.1 Hz, 2 H), 4.14 (s, 2 H), 1.35 (t, J=7.1 Hz, 3 H); IR (chloroform) 3390, 1727, 1523, 1345, 1309 cm-1 ; MS (ESMS) 250.0 (M+H)+.

Workup

  1. temperaturethe solution was cooled thoroughly for an additional 10-15 minutes
  2. addition1.09 g, 5.34 mmol, 1 equiv.) was added portionwise over several minutes The resulting yellow solution
  3. additionthen was poured carefully
  4. extractionthe mixture was extracted with ethyl acetate (3×50 mL)
  5. customDrying
  6. concentration(sodium sulfate), concentration, and silica gel chromatography (3:2 ethyl acetate/toluene)

Sources & evidence

ORD record
ord-b91d2a48e9bf4595ab7ca4e60eaf14e6
Source dataset
uspto-grants-1998_04
Patent number
US05741804

Reaction notes

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