4-Fluorophenylhydrazine hydrochloride → 1-(4-Fluorophenyl)-3-isopropyl-6-oxo-5-phenyl-4,6-dihydro-1H-pyrazolo[3,4-c]pyrrole

HRID 1720947Notes

Reaction equation

HRID 1720947 reaction equation
O[C:2]1[C:3](=[O:18])[N:4]([C:12]2[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=2)[CH2:5][C:6]=1[C:7](=O)[CH:8]([CH3:10])[CH3:9].Cl.[F:20][C:21]1[CH:26]=[CH:25][C:24]([NH:27][NH2:28])=[CH:23][CH:22]=1.C[O-].[Na+]>C(O)C>[F:20][C:21]1[CH:26]=[CH:25][C:24]([N:27]2[C:2]3[C:3](=[O:18])[N:4]([C:12]4[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=4)[CH2:5][C:6]=3[C:7]([CH:8]([CH3:10])[CH3:9])=[N:28]2)=[CH:23][CH:22]=1.[F:20][C:21]1[CH:26]=[CH:25][C:24]([N:27]2[C:7]([CH:8]([CH3:10])[CH3:9])=[C:6]3[C:2]([C:3](=[O:18])[N:4]([C:12]4[CH:17]=[CH:16][CH:15]=[CH:14][CH:13]=4)[CH2:5]3)=[N:28]2)=[CH:23][CH:22]=1

Participants

6

Reactant 3

HCID 699814-Fluorophenylhydrazine hydrochlorideHCID 10942334Sodium MethoxideHCID 153380843-Hydroxy-4-isobutyryl-2-oxo-1-phenyl-2,5-dihydropyrrole

Product 2

HCID 98841521-(4-Fluorophenyl)-3-isopropyl-6-oxo-5-phenyl-4,6-dihydro-1H-pyrazolo[3,4-c]pyrroleHCID 153380852-(4-fluorophenyl)-3-isopropyl-6-oxo-5-phenyl-4,6-dihydro-2H-pyrazolo[3,4-c]pyrrole

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 3-hydroxy-4-isobutyryl-2-oxo-1-phenyl-2,5-dihydropyrrole (0.350 g, 1.43 mmole), 4-fluorophenylhydrazine hydrochloride (0.245 g, 1.50 mmole) and sodium methoxide (39 mg, 0.72 mmole) in ethanol (10 ml) was heated to reflux. After 16 hours the solvent was removed by rotory evaporation under reduced pressure, and the crude residue was chromatographed on a silica column using 1:3 ethyl acetate/hexane as eluent to give 210 mg of the title compound along with 80 mg of the 2-(4-fluorophenyl)-3-isopropyl-6-oxo-5-phenyl-4,6-dihydro-2H-pyrazolo[3,4-c]pyrrole regioisomer (M.P. 223°-224° C.). The title compound was recrystallized from ether to give a pale yellow solid. M.P. 150°-151° C.; 1H NMR (250 Mhz, CDCl3) δ 1.38 (d, J=7.0 Hz, 6H), 3.18 (heptet, J=7.0 Hz, 1H), 4.78 (s, 2H), 7.15 (dd, J=8.3, 9.1 Hz, 2H), 7.21 (m, 1H), 7.43 (t, J=7.9 Hz, 2H), 7.74 (d, J=7.8 Hz, 2H), 8.20 (dd, J=4.8, 9.1 Hz, 2H); MS m/z (M+) 336.

Workup

  1. temperaturewas heated to reflux
  2. customAfter 16 hours the solvent was removed by rotory evaporation under reduced pressure
  3. customthe crude residue was chromatographed on a silica column

Sources & evidence

ORD record
ord-b5ee56d8b25242bdbf17001f2d34f011
Source dataset
uspto-grants-1996_04
Patent number
US05508300

Reaction notes

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