p-Toluenesulfonic acid → 5-Iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-indazole

HRID 1254433Notes

Reaction equation

HRID 1254433 reaction equation
[I:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[NH:7][N:6]=[CH:5]2.[CH2:11]1[CH2:16][O:15][CH:14]=[CH:13][CH2:12]1.CC1C=CC(S(O)(=O)=O)=CC=1.C([O-])(O)=O.[Na+]>ClCCl>[I:1][C:2]1[CH:3]=[C:4]2[C:8](=[CH:9][CH:10]=1)[N:7]([CH:14]1[CH2:13][CH2:12][CH2:11][CH2:16][O:15]1)[N:6]=[CH:5]2

Participants

6

Reactant 4

HCID 6101p-Toluenesulfonic acidHCID 80803,4-dihydro-2H-pyranHCID 516892Sodium BicarbonateHCID 218947395-Iodo-1H-indazole

Product 1

HCID 667934695-Iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-indazoleYield 82.6%

Reagents, catalysts & solvents 1

HCID 6344DichloromethaneSolvent

Procedure

To a mixture of 5-iodo-1H-indazole (0.90 g, 3.69 mmol) and DHP (1.57 g, 18.7 mmol) in dry dichloromethane (20 mL), was added PTSA (0.08 g, 0.41 mmol) at room temperature. The resulting mixture was stirred overnight. Upon completion, saturated aqueous NaHCO3 (30 mL) was added slowly into the reaction mixture. The organic layer was separated, dried over Na2SO4, and concentrated in vacuo. The residue was purified by column chromatography on silica gel (0-5% EtOAc in petroleum ether) affording the title compound (1.0 g). 1H NMR (400 MHz, DMSO-d6): δ 8.21 (s, 1H), 8.08 (s, 1H), 7.67 (dd, 1H), 7.61 (d, 1H), 5.85 (dd, 1H), 3.88-3.85 (m, 1H), 3.78-3.72 (m, 1H), 2.41-2.29 (m, 1H), 2.05-1.95 (m, 2H), 1.77-1.72 (m, 1H), 1.61-1.56 (m, 2H).

Workup

  1. customThe organic layer was separated
  2. dry with materialdried over Na2SO4
  3. concentrationconcentrated in vacuo
  4. customThe residue was purified by column chromatography on silica gel (0-5% EtOAc in petroleum ether)

Sources & evidence

ORD record
ord-c679f31679f84938a4bc51e5539a5971
Source dataset
uspto-grants-2013_06
Patent number
US08455534B2

Reaction notes

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