2(3H)-benzoxazolone, 3-methyl-5-nitro- → 5-Amino-3-methyl-2,3-dihydro-1,3-benzoxazol-2-one
Reaction equation
[CH3:1][N:2]1[C:6]2[CH:7]=[C:8]([N+:11]([O-])=O)[CH:9]=[CH:10][C:5]=2[O:4][C:3]1=[O:14].[H][H]>C(O)(=O)C.[Pd]>[NH2:11][C:8]1[CH:9]=[CH:10][C:5]2[O:4][C:3](=[O:14])[N:2]([CH3:1])[C:6]=2[CH:7]=1Participants
Reactant 2
Product 1
Reagents, catalysts & solvents 2
Procedure
3-Methyl-5-nitro-3H-benzooxazol-2-one (22.87 g) was dissolved in acetic acid (350 mL). Palladium on activated charcoal 10% (6.27 g) was added and an atmosphere of hydrogen was introduced at r.t. The mixture was stirred over night. The reaction mixture was filtered over dicalite speed plus (Acros) and the solvent was evaporated. The residue was dissolved in 2M aqueous HCl (500 mL) and stirred for 10 minutes. The resulting solution was basified with conc. aqueous NaOH (200 mL) to pH 11 and stirred for 20 minutes at r.t. The resulting precipitate was filtered off and washed with cold water. Residual water was removed by co-evaporation with toluene. The resulting solid was dried in vacuo. The title compound was obtained as a brown solid (18.72 g, 92%). MS (m/e)=165.2 [M+H+].
Workup
- filtrationThe reaction mixture was filtered over dicalite speed plus (Acros)
- customthe solvent was evaporated
- dissolutionThe residue was dissolved in 2M aqueous HCl (500 mL)
- stirringstirred for 10 minutes
- stirringstirred for 20 minutes at r.t
- filtrationThe resulting precipitate was filtered off
- washwashed with cold water
- customResidual water was removed by co-evaporation with toluene
- customThe resulting solid was dried in vacuo
Sources & evidence
- ORD record
- ord-9152de88a8a84fc38b29bf4aea5965f9
- Source dataset
- uspto-grants-2012_09
- Patent number
- US08268820B2
Reaction notes
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