Diglyme → 4-(1H-benzimidazol-2-yl)-1,2,5-oxadiazol-3-amine

HRID 2405028Notes

Reaction equation

HRID 2405028 reaction equation
Cl.[NH2:2]O.[OH-].[K+].COCCOCCOC.[NH:15]1[C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][C:18]=2[N:17]=[C:16]1[C:24](=[N:27][OH:28])[C:25]#[N:26]>O>[NH:15]1[C:19]2[CH:20]=[CH:21][CH:22]=[CH:23][C:18]=2[N:17]=[C:16]1[C:24]1[C:25]([NH2:2])=[N:26][O:28][N:27]=1

Participants

6

Reactant 4

HCID 8150DiglymeHCID 14797Potassium HydroxideHCID 443297Hydroxyamine hydrochlorideHCID 828331HCID 828331, compound

Product 1

HCID 7385314-(1H-benzimidazol-2-yl)-1,2,5-oxadiazol-3-amineYield 48.6%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Conditions

Temperature
170 °C

Procedure

To an ice-cooled stirred solution of 13.2 g of hydroxylamine hydrochloride (190 mmol, 3 eq) in 20 ml of water, 15.3 g of potassium hydroxide (27.2 mmol, 4.3 eq) are slowly added. Then 60 ml of diglyme (diethylene glycol dimethyl ether) and 11.8 g of (1H-benzoimidazol-2-yl)-hydroxyimino-acetonitrile (63.4 mmol, 1 eq) are added. The ice-bath is removed and the reaction mixture is heated to reflux for 8 h (bath temperature 170° C.). After cooling to room temperature, the reaction mixture is filtered and the residue is washed with water to give the first crop of the desired product (6.2 g). The filtrate is treated with 150 ml of water. The resulting suspension is filtered and washed with water to provide a second product crop (2.17 g). Both crops are combined and used in the next step.

Workup

  1. additionare slowly added
  2. customThe ice-bath is removed
  3. temperaturethe reaction mixture is heated
  4. temperatureAfter cooling to room temperature
  5. filtrationthe reaction mixture is filtered
  6. washthe residue is washed with water

Sources & evidence

ORD record
ord-f6da0b282c9c4f0d99ec755b9dea42b0
Source dataset
uspto-grants-2014_08
Patent number
US08802858B2

Reaction notes

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