反应详情

Treatment of 3,5-dibromo-4-nitro-1H-pyrazole 1 with MeI and NaH in DMF affords 3,5-dibromo-1-methyl-4-nitro-1H-pyrazole 2. Nucleophilic aromatic substitution of the compound 2 with benzylamine in DMSO produces benzyl-(5-bromo-2-methyl-4-nitro-2H-pyrazol-3-yl)-amine 3. Treatment of the compound 3 with phenol in the presence of copper (I) iodide and cecium carbonate in N-methylpyrrolidinone (NMP) under microwave irradiation provides N-benzyl-1-methyl-4-nitro-3-phenoxy-1H-pyrazol-5-amine 4 (Tetrahedron Lett, 2003, 44, 3445). Hydrogenation of the compound 4 with Pd/C at 60 psi hydrogen in ethanol affords 1-methyl-3-phenoxy-1H-pyrazole-4,5-diamine 5. II. Keratin Dyeing Composition Components