p-Toluenesulfonic acid → ethyl 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylate

HRID 526764Notes

Reaction equation

HRID 526764 reaction equation
[I:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][NH:4][N:3]=1.[CH3:12][C:13]1C=C[C:16](S(O)(=O)=O)=[CH:17][CH:18]=1.C1C[O:26]CC1>>[I:1][C:2]1[C:6]([C:7]([O:9][CH2:10][CH3:11])=[O:8])=[CH:5][N:4]([CH:16]2[CH2:17][CH2:18][CH2:13][CH2:12][O:26]2)[N:3]=1

Participants

4

Reactant 3

HCID 6101p-Toluenesulfonic acidHCID 8028TetrahydrofuranHCID 178469927HCID 178469927, compound

Product 1

HCID 58486565ethyl 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylateYield 98%

Procedure

A solution of ethyl 3-iodo-1H-pyrazole-4-carboxylate (27 g, 101.8 mmol), 3,4-DHP (25.71 g 305.6 mmol) and PTSA (1.94 g 10.18 mmol) in THF (100 mL) was heated at 60° C. for 5 h. Solvent was evaporated under vacuum and the residue redissolved in DCM (500 mL) was added. The solution was washed with sat.NaHCO3 (200 mL×2), dried, concentrated to afford crude ethyl 3-iodo-1-(tetrahydro-2H-pyran-2-yl)-1H-pyrazole-4-carboxylate (35 g, yield: 98%). The crude material was used in the next synthetic step without further purification.

Workup

  1. customSolvent was evaporated under vacuum
  2. dissolutionthe residue redissolved in DCM (500 mL)
  3. additionwas added
  4. washThe solution was washed
  5. dry with materialNaHCO3 (200 mL×2), dried
  6. concentrationconcentrated

Sources & evidence

ORD record
ord-0a3d5917023e49e2b847a3bbf801dc33
Source dataset
uspto-grants-2016_05
Patent number
US09346761B2

Reaction notes

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