Cesium carbonate → 1-cyclopentyl-5-iodo-1H-indazole

HRID 1661460Notes

Reaction equation

HRID 1661460 reaction equation
F[C:2]1[CH:9]=[CH:8][C:7]([I:10])=[CH:6][C:3]=1[CH:4]=O.[CH:11]1([NH:16][NH2:17])[CH2:15][CH2:14][CH2:13][CH2:12]1.C(=O)([O-])[O-].[Cs+].[Cs+].CC([O-])(C)C.[K+]>CN1C(=O)CCC1.C(OCC)(=O)C.C(#N)C.CN(C=O)C>[CH:11]1([N:16]2[C:2]3[C:3](=[CH:6][C:7]([I:10])=[CH:8][CH:9]=3)[CH:4]=[N:17]2)[CH2:15][CH2:14][CH2:13][CH2:12]1

Participants

9

Reactant 4

HCID 10796Cesium carbonateHCID 212350CyclopentylhydrazineHCID 162170582-Fluoro-5-iodobenzaldehydeHCID 23665647Potassium tert-butoxide

Product 1

HCID 593397901-cyclopentyl-5-iodo-1H-indazole

Reagents, catalysts & solvents 4

HCID 6228DimethylformamideSolventHCID 6342AcetonitrileSolventHCID 8857Ethyl AcetateSolventHCID 13387N-methyl-2-pyrrolidoneSolvent

Conditions

Temperature
100 °C

Procedure

A mixture of 2-fluoro-5-iodobenzaldehyde (500 mg, 2 mmol), cyclopentylhydrazine (273 mg, 2 mmol), and cesium carbonate (1.91 g, 5 mmol) in NMP (5ml) was stirred at 100° C. overnight. Then KOtBu (560 mg, 5 mmol) and DMF (10 ml) were added, and the mixture was stirred at 150° C. for 5 h. After cooling to room temp., the mixture was diluted with ethyl acetate (100 ml), and washed with water (3×50 ml), and dried. Evaporation of solvent afforded batch residue, which was dissolved in acetonitrile (50 ml), and the insoluble material was removed vy filtration. Flash chromatography on silica gel (n-heptane/ethyl acetate) afforded yellow oil, 158 mg (25%).

Workup

  1. stirringthe mixture was stirred at 150° C. for 5 h
  2. temperatureAfter cooling to room temp.
  3. washwashed with water (3×50 ml)
  4. customdried
  5. customEvaporation of solvent
  6. customafforded batch residue, which
  7. customthe insoluble material was removed
  8. filtrationvy filtration
  9. customFlash chromatography on silica gel (n-heptane/ethyl acetate) afforded yellow oil, 158 mg (25%)

Sources & evidence

ORD record
ord-dd1387ddcae447e6bf52555799ca2b94
Source dataset
uspto-grants-2011_10
Patent number
US08030340B2

Reaction notes

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