Potassium sodium tartarate → (5-bromo-1-methyl-1H-pyrazol-4-yl)methanol

HRID 72721Notes

Reaction equation

HRID 72721 reaction equation
[Br:1][C:2]1[N:6]([CH3:7])[N:5]=[CH:4][C:3]=1[C:8](OCC)=[O:9].[H-].C([Al+]CC(C)C)C(C)C.C(C(C(C([O-])=O)O)O)([O-])=O.[K+].[Na+]>O1CCCC1>[Br:1][C:2]1[N:6]([CH3:7])[N:5]=[CH:4][C:3]=1[CH2:8][OH:9]

Participants

5

Reactant 3

HCID 9855836Potassium sodium tartarateHCID 21225700DiisobutylaluminumhydrideHCID 53302113Ethyl 5-Bromo-1-methyl-1H-pyrazole-4-carboxylate

Product 1

HCID 84662962(5-bromo-1-methyl-1H-pyrazol-4-yl)methanol

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of ethyl 5-bromo-1-methyl-1H-pyrazole-4-carboxylate (2.00 g, 8.58 mmol) in tetrahydrofuran (30 mL) at 0° C. was treated with diisobutylaluminum hydride (1 M solution in tetrahydrofuran, 18.9 mL, 18.9 mmol), and the mixture was allowed to warm to room temperature and stir for 18 hours. Saturated aqueous sodium potassium tartrate solution was added, and stirring was continued for 4 hours. The aqueous layer was extracted with ethyl acetate, and the combined organic layers were dried over magnesium sulfate, filtered, and concentrated under reduced pressure. Purification via silica gel chromatography (Eluent: 100:1 ethyl acetate/methanol) afforded the product. Yield: 1.63 g, 8.53 mmol, 99%. LCMS m/z 192.9 (M+1). 1H NMR (400 MHz, CDCl3) δ 2.44 (s, 1H), 3.84 (s, 3H), 4.48 (s, 2H), 7.51 (s, 1H).

Workup

  1. stirringstirring
  2. waitwas continued for 4 hours
  3. extractionThe aqueous layer was extracted with ethyl acetate
  4. dry with materialthe combined organic layers were dried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated under reduced pressure
  7. customPurification via silica gel chromatography (Eluent: 100:1 ethyl acetate/methanol)
  8. customafforded the product

Sources & evidence

ORD record
ord-05bc563ebc814784873be429d31ae7f8
Source dataset
uspto-grants-2014_09
Patent number
US08829010B2

Reaction notes

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