2-Methyl-6-nitrobenzoxazole → 2-Methyl-1,3-benzoxazol-6-amine

HRID 2110454Notes

Reaction equation

HRID 2110454 reaction equation
[CH3:1][C:2]1[O:3][C:4]2[CH:10]=[C:9]([N+:11]([O-])=O)[CH:8]=[CH:7][C:5]=2[N:6]=1>CC(O)=O.[Fe]>[CH3:1][C:2]1[O:3][C:4]2[CH:10]=[C:9]([NH2:11])[CH:8]=[CH:7][C:5]=2[N:6]=1

Participants

4

Reactant 1

HCID 797662-Methyl-6-nitrobenzoxazole

Product 1

HCID 5905392-Methyl-1,3-benzoxazol-6-amineYield 83.2%

Reagents, catalysts & solvents 2

HCID 23925IronCatalyst2×HCID 176Acetic AcidSolvent

Procedure

To a solution of 2-methyl-6-nitrobenzoxazole (100 mg, 0.560 mmol) in AcOH (2 mL) was added iron powder (325 mesh, 63.0 mg, 1.12 mmol) at 70° C. in a single portion. After 15 min at 70° C. additional iron powder (325 mesh, 63.0 mg, 1.12 mmol) was added and stirring was continued for 15 min. The mixture was cooled and concentrated under reduced pressure. The resulting residue was taken up into EtOAc and washed with sat. Na2CO3 followed by H2O. The organic layer was dried over MgSO4, concentrated under reduced pressure and purified by flash chromatography on silica gel eluting with a gradient of 0 to 25% EtOAc in CH2Cl2 to yield 69 mg (83%) of compound 479A as a solid. HPLC: 97% at 0.24 min (retention time) (YMC S5 ODS column, 4.6×50 mm Ballistic, 10-90% aqueous methanol over 4 min containing 0.2% H3PO4, 4 mL/min, monitoring at 220 nm). MS (ES): m/z 149.2 [M+H]+.

Workup

  1. temperatureThe mixture was cooled
  2. concentrationconcentrated under reduced pressure
  3. washwashed with sat. Na2CO3
  4. dry with materialThe organic layer was dried over MgSO4
  5. concentrationconcentrated under reduced pressure
  6. custompurified by flash chromatography on silica gel eluting with a gradient of 0 to 25% EtOAc in CH2Cl2

Sources & evidence

ORD record
ord-1a247eb7cf2a4afcb2669925ae9c2c3b
Source dataset
uspto-grants-2009_04
Patent number
US07517904B2

Reaction notes

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