Sodium Carbonate → 1-Cyclopentyl-3-ethyl-6-(2-thienyl)-1H-indazole

HRID 1385120Notes

Reaction equation

HRID 1385120 reaction equation
[S:1]1[CH:5]=[CH:4][CH:3]=[C:2]1B(O)O.Br[C:10]1[CH:18]=[C:17]2[C:13]([C:14]([CH2:24][CH3:25])=[N:15][N:16]2[CH:19]2[CH2:23][CH2:22][CH2:21][CH2:20]2)=[CH:12][CH:11]=1.C([O-])([O-])=O.[Na+].[Na+]>CO.C(OCC)(=O)C>[CH:19]1([N:16]2[C:17]3[C:13](=[CH:12][CH:11]=[C:10]([C:2]4[S:1][CH:5]=[CH:4][CH:3]=4)[CH:18]=3)[C:14]([CH2:24][CH3:25])=[N:15]2)[CH2:23][CH2:22][CH2:21][CH2:20]1

Participants

6

Reactant 3

HCID 10340Sodium CarbonateHCID 27339602-Thiopheneboronic acidHCID 22733808HCID 22733808, compound

Product 1

HCID 211837081-Cyclopentyl-3-ethyl-6-(2-thienyl)-1H-indazoleYield 55%

Reagents, catalysts & solvents 2

HCID 887MethanolSolventHCID 8857Ethyl AcetateSolvent

Procedure

A solution of 76 mg (0.598 mmol, 1.2 equiv) thiophene-2-boronic acid in 0.5 mL methanol was added to a room temperature suspension of 146 mg (0.498 mmol, 1.0 equiv) 6-bromo-1-cyclopentyl-3-ethyl-1H-indazole and 17 mg (0.0149 mmol, 0.03 equiv) Pd(PPh3)4in 2 mL toluene and 0.5 mL 2M aqueous Na2CO3. The mixture was heated to reflux for 4 h, then cooled to room temperature. The reaction mixture was diluted with 50 mL ethyl acetate, washed 1×10 mL each H2O, brine, and dried over MgSO4. The crude product was purified on a silica gel column (3% ethylacetate/hexanes, flash) to give 81 mg (55%) of a clear oil, which crystalized onstanding: mp 60-64° C.; HRMS calcd for C18H20N2S+H: 297.1427. Found: 297.1484.

Workup

  1. temperatureThe mixture was heated
  2. temperatureto reflux for 4 h
  3. washwashed 1×10 mL each H2O, brine
  4. dry with materialdried over MgSO4
  5. customThe crude product was purified on a silica gel column (3% ethylacetate/hexanes, flash)

Sources & evidence

ORD record
ord-5d6136462d5747e89d80835f5e785bcc
Source dataset
uspto-grants-2001_07
Patent number
US06262040B1

Reaction notes

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