Réaction #1262012

Équation de réaction

4,4-dimethyl-3-oxopentanenitrile

4-nitrophenylhydrazine

acetic acid

→

desired product

Rendement 85.0%

5-tert-butyl-2-(4-nitro-Phenyl)-2H-pyrazol-3-ylamine

Rendement 85.0%

Solvants

EtOH

Conditions de réaction

Traitement

1. 1
   Températureat reflux under N2 for 18 h
2. 2
   Concentrationconcentrated at reduced pressure
3. 3
   AutreThe residue was partitioned between EtOAc (500 mL) and aqueous saturated NaHCO3 solution (300 mL)
4. 4
   LavageThe organic layer was washed with water and brine
5. 5
   Séchagedried over Na2SO4
6. 6
   Concentrationconcentrated at reduced pressure
7. 7
   AutreThe crude residue was purified by MPLC (eluting with 80:20 hexanes/EtOAc)

Mode opératoire

To a solution of 4,4-dimethyl-3-oxopentanenitrile (20.4 g, 163 mmol) and 4-nitrophenylhydrazine (25.0 g, 163 mmol) in anhydrous EtOH (300 mL) was added acetic acid (3.4 mL, 60 mL) dropwise. The reaction was stirred at reflux under N2 for 18 h. The reaction mixture was cooled to room temperature and concentrated at reduced pressure. The residue was partitioned between EtOAc (500 mL) and aqueous saturated NaHCO3 solution (300 mL). The organic layer was washed with water and brine, dried over Na2SO4, and concentrated at reduced pressure. The crude residue was purified by MPLC (eluting with 80:20 hexanes/EtOAc) to give 36.0 g (85%) of the desired product. 1H-NMR (DMSO-d6) δ 8.28 (d, J=6.9 Hz, 2H), 7.93 (d, J=6.9 Hz, 2H), 5.55 (s, 2H), 5.46 (s, 1H), 1.20 (s, 9H); MS LC-MS [M+H]+=261, RT=2.74 min.

Source