Phenylhydrazine → 1-Phenyl-1H-pyrazole-3,5-diamine

Temperatur

95 °C

Triethylamine (6 ml) was added over 5 minutes to a stirred suspension of diethyl malonimidate dihydrochloride (5 g) in ethanol (50 ml). Phenylhydrazine (2.1 ml) was added, then the mixture was stirred at ambient temperature for 4 hours and at 95° C. for 30 minutes. The solvent was removed in vacuo, and the residue was partitioned between ethyl acetate (100 ml) and water (50 ml). The organic layer was separated, washed with water (50 ml), dried (MgSO4), and the solvent was removed in vacuo. The residue was purified by flash chromatography over silica using a 19:1 mixture of dichloromethane and methanol as eluant, appropriate fractions were combined, and the solvents were removed in vacuo to give 3,5-diamino-1-phenylpyrazole as a red-brown oil (0.76 g).

1. customThe solvent was removed in vacuo
2. customthe residue was partitioned between ethyl acetate (100 ml) and water (50 ml)
3. customThe organic layer was separated
4. washwashed with water (50 ml)
5. dry with materialdried (MgSO4)
6. customthe solvent was removed in vacuo
7. customThe residue was purified by flash chromatography over silica using
8. additiona 19:1 mixture of dichloromethane and methanol as eluant
9. customthe solvents were removed in vacuo

ORD-Eintrag

ord-bf15116550614f689ee6e98a7444f0dd

Quelldatensatz

uspto-grants-2000_09

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US06114334