Sodium Bicarbonate → HCID 178469296, compound

HRID 1880349Notes

Reaction equation

HRID 1880349 reaction equation
[CH2:1]([O:3][C:4]([C:6](=[CH:11][C:12]1[C:13]([CH3:17])=[N:14][NH:15][CH:16]=1)[CH2:7][C:8]([OH:10])=O)=[O:5])[CH3:2].C([O-])(=O)C.[Na+].C([O-])(O)=O.[Na+]>C(OC(=O)C)(=O)C>[CH3:17][C:13]1[C:12]2[C:16](=[C:8]([OH:10])[CH:7]=[C:6]([C:4]([O:3][CH2:1][CH3:2])=[O:5])[CH:11]=2)[NH:15][N:14]=1

Participants

5

Reactant 3

HCID 516892Sodium BicarbonateHCID 517045Sodium AcetateHCID 178471162HCID 178471162, compound

Product 1

HCID 178469296HCID 178469296, compoundYield 54.1%

Reagents, catalysts & solvents 1

HCID 7918Acetic AnhydrideSolvent

Procedure

A solution of 3-(ethoxycarbonyl)-4-(3-methyl-1H-pyrazol-4-yl)but-3-enoic acid (20 g, 84 mmol) in acetic anhydride (80 mL), sodium acetate (13.8 g, 168 mmol) was added at room temperature and the mixture was heated at reflux for 4 hours. The reaction mixture was cooled to room temperature, basified (pH˜9) using aqueous NaHCO3 solution and extracted with ethyl acetate (2×100 mL). The combined organic layers were washed with water (50 mL), saturated aqueous NaCl (50 mL), dried over anhydrous Na2SO4 and concentrated to obtain crude product; which was purified by column chromatography (100-200 mesh silica gel) using 6-8% ethyl acetate in pet-ether as eluents to afford ethyl 3-methyl-7-hydroxy-1H-indazole-5-carboxylate (10 g, 40%) as orange solid. 1H NMR (CDCl3) δ 8.25 (s, 1H), 7.9 (s, 1H), 4.4 (q, 2H), 2.75 (s, 3H), 2.6 (s, 3H), 2.4 (s, 3H), 1.4 (t, 3H).

Workup

  1. temperaturethe mixture was heated
  2. temperatureat reflux for 4 hours
  3. extractionextracted with ethyl acetate (2×100 mL)
  4. washThe combined organic layers were washed with water (50 mL), saturated aqueous NaCl (50 mL)
  5. dry with materialdried over anhydrous Na2SO4
  6. concentrationconcentrated
  7. customto obtain crude product
  8. customwhich was purified by column chromatography (100-200 mesh silica gel)

Sources & evidence

ORD record
ord-81144b1da1994e5590905f44907934a3
Source dataset
uspto-grants-2012_11
Patent number
US08318762B2

Reaction notes

Loading…