Water → 6-bromo-2-isopropyl-4-nitro-1H-benzo[d]imidazole

HRID 2088546Notes

Reaction equation

HRID 2088546 reaction equation
[Br:1][C:2]1[CH:7]=[C:6]([NH2:8])[C:5]([NH2:9])=[C:4]([N+:10]([O-:12])=[O:11])[CH:3]=1.O.C([O-])([O-])=O.[Na+].[Na+].[C:20](O)(=O)[CH:21]([CH3:23])[CH3:22]>>[Br:1][C:2]1[CH:3]=[C:4]([N+:10]([O-:12])=[O:11])[C:5]2[N:9]=[C:20]([CH:21]([CH3:23])[CH3:22])[NH:8][C:6]=2[CH:7]=1

Participants

5

Reactant 4

HCID 962WaterHCID 6590Isobutyric AcidHCID 10340Sodium CarbonateHCID 457894035-Bromo-3-nitrobenzene-1,2-diamine

Product 1

HCID 669767256-bromo-2-isopropyl-4-nitro-1H-benzo[d]imidazoleYield 77%

Conditions

Temperature
120 °C

Procedure

A mixture of 5-bromo-3-nitrobenzene-1,2-diamine (prepared following the same procedure as for Example 1, 5.0 g) in isobutyric acid (20 mL) was stirred at 120° C. overnight. The mixture was cooled to room temperature and poured into water (100 mL). The pH was neutralized with aqueous Na2CO3 solution. It was then extracted with EtOAc and the organic layer was washed with water and brine, dried over anhydrous MgSO4, filtered and concentrated in-vacuo. The residue was then purified by silica gel chromatography eluted with EtOAc:petroleum ether=1:1 to afford the desired product as a yellow solid (4.7 g, 77%). 1H NMR (300 MHz, CDCl3) δ ppm 1.51 (m, 6H, J=6.9 Hz), 3.32 (m, 1H, J=6.9 Hz), 8.16 (d, 1H, J=1.5 Hz), 8.25 (d, 1H, J=1.5 Hz), 10.26 (br s, 1H); LC-MS: m/e=284 [M+1]+

Workup

  1. customprepared
  2. temperatureThe mixture was cooled to room temperature
  3. extractionIt was then extracted with EtOAc
  4. washthe organic layer was washed with water and brine
  5. dry with materialdried over anhydrous MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated in-vacuo
  8. customThe residue was then purified by silica gel chromatography
  9. washeluted with EtOAc

Sources & evidence

ORD record
ord-34c4a46617134d6cbd810c60a9f9f3df
Source dataset
uspto-grants-2013_05
Patent number
US08435988B2

Reaction notes

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