2-Chlorobenzoxazole → 2-(2-Methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethoxy)benzoxazole

HRID 856174Notes

Reaction equation

HRID 856174 reaction equation
[H-].[Na+].[OH:3][CH2:4][C:5]1([CH3:16])[O:9][C:8]2=[N:10][C:11]([N+:13]([O-:15])=[O:14])=[CH:12][N:7]2[CH2:6]1.Cl[C:18]1[O:19][C:20]2[CH:26]=[CH:25][CH:24]=[CH:23][C:21]=2[N:22]=1>CN(C=O)C>[CH3:16][C:5]1([CH2:4][O:3][C:18]2[O:19][C:20]3[CH:26]=[CH:25][CH:24]=[CH:23][C:21]=3[N:22]=2)[O:9][C:8]2=[N:10][C:11]([N+:13]([O-:15])=[O:14])=[CH:12][N:7]2[CH2:6]1

Participants

5

Reactant 3

HCID 119862-ChlorobenzoxazoleHCID 24758Sodium hydrideHCID 23081240(2-Methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-yl)methanol

Product 1

HCID 230813102-(2-Methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethoxy)benzoxazoleYield 39.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent2×

Conditions

Temperature
0 °C

Procedure

Sodium hydride (77 mg, 1.9 mmol) was added to a solution of 2-hydroxymethyl-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazole prepared in Example 33 (0.32 g, 1.6 mmol) in DMF (3 ml) with cooling on ice-bath followed by stirring at 0° C. for 30 minutes. To the reaction mixture, 2-chlorobenzoxazole (0.30 g, 1.9 mmol) in DMF (3 ml) was added with cooling on ice-bath followed by stirring at room temperature for 44 hours. Ice-water was added to the reaction mixture, and the resulting mixture was extracted with ethyl acetate. The organic phase was washed with water, dried over magnesium sulfate and then concentrated. The residue was purified by silica gel column chromatography (methylene chloride/methanol=100/1) and recrystallized from acetonitrile-isopropanol to afford 2-(2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-ylmethoxy)benzoxazole (0.20 g, 39%) as a light yellow solid.

Workup

  1. temperaturewith cooling on ice-bath
  2. temperaturewith cooling on ice-bath
  3. stirringby stirring at room temperature for 44 hours
  4. extractionthe resulting mixture was extracted with ethyl acetate
  5. washThe organic phase was washed with water
  6. dry with materialdried over magnesium sulfate
  7. concentrationconcentrated
  8. customThe residue was purified by silica gel column chromatography (methylene chloride/methanol=100/1)
  9. customrecrystallized from acetonitrile-isopropanol

Sources & evidence

ORD record
ord-c1147c28aa564776b24ca5ba525b68b7
Source dataset
uspto-grants-2007_08
Patent number
US07262212B2

Reaction notes

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