Sodium hydride → 2-{[(5-Bromo-2-pyridinyl)oxy]methyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazole

HRID 2066629Notes

Reaction equation

HRID 2066629 reaction equation
[Br:1][C:2]1[CH:3]=[CH:4][C:5](F)=[N:6][CH:7]=1.[CH3:9][C:10]1([CH2:21][OH:22])[O:14][C:13]2=[N:15][C:16]([N+:18]([O-:20])=[O:19])=[CH:17][N:12]2[CH2:11]1.[H-].[Na+].C(=O)=O.CC(C)=O>CN(C=O)C>[Br:1][C:2]1[CH:3]=[CH:4][C:5]([O:22][CH2:21][C:10]2([CH3:9])[O:14][C:13]3=[N:15][C:16]([N+:18]([O-:20])=[O:19])=[CH:17][N:12]3[CH2:11]2)=[N:6][CH:7]=1

Participants

6

Reactant 4

HCID 24758Sodium hydrideHCID 27831685-Bromo-2-fluoropyridine2×HCID 18522661Acetone cardiceHCID 23081240(2-Methyl-6-nitro-2,3-dihydroimidazo[2,1-b]oxazol-2-yl)methanol

Product 1

HCID 669571002-{[(5-Bromo-2-pyridinyl)oxy]methyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazoleYield 36.2%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

5-Bromo-2-fluoropyridine (91) (0.25 mL, 2.43 mmol) was added to a solution of alcohol 101 (200 mg, 1.01 mmol) in anhydrous DMF (4.5 mL) under N2 at 0° C. The resulting mixture was treated with 60% NaH (64 mg, 1.60 mmol), then quickly degassed and resealed under N2. Further 5-bromo-2-fluoropyridine (91) (0.25 mL, 2.43 mmol) was added and the mixture was stirred at room temperature for 2 h, and then cooled (CO2/acetone), quenched with ice/aqueous NaHCO3 (15 mL), added to brine (40 mL) and extracted with CH2Cl2 (8×40 mL). The combined extracts were evaporated to dryness and the residue was chromatographed on silica gel. Elution with CH2Cl2 firstly gave foreruns, and then further elution with 0-1.5% EtOAc/CH2Cl2 gave 2-{[(5-bromo-2-pyridinyl)oxy]methyl}-2-methyl-6-nitro-2,3-dihydroimidazo[2,1-b][1,3]oxazole (102) (130 mg, 36%) as a cream solid: mp (CH2Cl2/hexane) 151-153° C.; 1H NMR (CDCl3) δ 8.17 (dd, J=2.5, 0.5 Hz, 1H), 7.68 (dd, J=8.8, 2.5 Hz, 1H), 7.52 (s, 1H), 6.60 (dd, J=8.7, 0.6 Hz, 1H), 4.58 (d, J=12.0 Hz, 1H), 4.50 (d, J=12.0 Hz, 1H), 4.41 (d, J=10.2 Hz, 1H), 4.01 (d, J=10.2 Hz, 1H), 1.76 (s, 3H). Anal. (C12H11BrN4O4) C, H, N.

Workup

  1. customquickly degassed
  2. customquenched with ice/aqueous NaHCO3 (15 mL)
  3. additionadded to brine (40 mL)
  4. extractionextracted with CH2Cl2 (8×40 mL)
  5. customThe combined extracts were evaporated to dryness
  6. customthe residue was chromatographed on silica gel
  7. washElution with CH2Cl2 firstly gave foreruns
  8. washfurther elution with 0-1.5% EtOAc/CH2Cl2

Sources & evidence

ORD record
ord-a859ad67e6864747bad967f0d16da97a
Source dataset
uspto-grants-2012_10
Patent number
US08293734B2

Reaction notes

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