p-Toluenesulfonic acid monohydrate → 2-methyl-7-(2,4,6-trimethyl-phenyl)-3-vinyl-2H-indazole

HRID 902552Notes

Reaction equation

HRID 902552 reaction equation
[CH3:1][N:2]1[C:10]([CH:11](O)[CH3:12])=[C:9]2[C:4]([C:5]([C:14]3[C:19]([CH3:20])=[CH:18][C:17]([CH3:21])=[CH:16][C:15]=3[CH3:22])=[CH:6][CH:7]=[CH:8]2)=[N:3]1.O.C1(C)C=CC(S(O)(=O)=O)=CC=1>C1(C)C=CC=CC=1>[CH3:1][N:2]1[C:10]([CH:11]=[CH2:12])=[C:9]2[C:4]([C:5]([C:14]3[C:19]([CH3:20])=[CH:18][C:17]([CH3:21])=[CH:16][C:15]=3[CH3:22])=[CH:6][CH:7]=[CH:8]2)=[N:3]1

Participants

4

Reactant 2

HCID 521998p-Toluenesulfonic acid monohydrateHCID 597022851-[2-methyl-7-(2,4,6-trimethyl-phenyl)-2H-indazol-3-yl]-ethanol

Product 1

HCID 597023452-methyl-7-(2,4,6-trimethyl-phenyl)-3-vinyl-2H-indazoleYield 55%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Procedure

A solution of 1-[2-methyl-7-(2,4,6-trimethyl-phenyl)-2H-indazol-3-yl]-ethanol (0.263 g, 0.893 mmol) and 4-toluenesulfonic acid hydrate (0.217 g, 1.14 mmol) in 10 mL of toluene was stirred at 103° C. for 16 h then allowed to cool. The yellow-orange solution was sequentially washed with 10 mL of a 10% aqueous NaOH solution and 10 mL of a saturated aqueous NaCl solution, dried over MgSO4, filtered, and concentrated to an orange oil. Column chromatography (20% EtOAc/hexanes) afforded 2-methyl-7-(2,4,6-trimethyl-phenyl)-3-vinyl-2H-indazole (15: Ra=Rb=H, Ar=2,4,6-trimethylphenyl; 0.135 g; 55%; m.p. 84.9-95.4) as a pale yellow solid.

Workup

  1. temperatureto cool
  2. washThe yellow-orange solution was sequentially washed with 10 mL of a 10% aqueous NaOH solution and 10 mL of a saturated aqueous NaCl solution
  3. dry with materialdried over MgSO4
  4. filtrationfiltered
  5. concentrationconcentrated to an orange oil

Sources & evidence

ORD record
ord-b172ceb4c6424a74af9bb016fbb0c39c
Source dataset
uspto-grants-2008_04
Patent number
US07365211B2

Reaction notes

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