Hydrochloric Acid → 2-(3-nitro-1H-pyrazol-1-yl)ethanol

HRID 1261477Notes

Reaction equation

HRID 1261477 reaction equation
C([Si](C)(C)[O:6][CH2:7][CH2:8][N:9]1[CH:13]=[CH:12][C:11]([N+:14]([O-:16])=[O:15])=[N:10]1)(C)(C)C.Cl>C(O)C.Cl>[N+:14]([C:11]1[CH:12]=[CH:13][N:9]([CH2:8][CH2:7][OH:6])[N:10]=1)([O-:16])=[O:15]

Participants

5

Reactant 2

HCID 313Hydrochloric AcidHCID 593449511-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-3-nitro-1H-pyrazole

Product 1

HCID 163948492-(3-nitro-1H-pyrazol-1-yl)ethanolYield 94%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidCatalystHCID 702EthanolSolvent

Procedure

A solution of 1-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-3-nitro-1H-pyrazole (prepared as in US 20080021032 Example 67, 6.34 g, 23.36 mmol) in ethanol (100 mL) was treated with concentrated hydrochloric acid (12 drops) and stirred for 1 h at room temperature. After this time, another portion of concentrated hydrochloric acid was added (12 drops) and it was stirred overnight at room temperature. After this time, the reaction mixture was concentrated in vacuo and then azeotroped with acetonitrile. The crude material was then purified by flash column chromatography (silica gel 60, 230-400 mesh, 80% ethyl acetate/hexanes) to afford 2-(3-nitro-pyrazol-1-yl)-ethanol (2.36 g, 94%) as a white solid: 1H NMR (300 MHz, DMSO-d6) δ ppm 8.00 (d, J=2.56 Hz, 1H), 7.03 (d, J=2.56 Hz, 1H), 5.00 (t, J=5.31 Hz, 1H), 4.26 (t, J=5.31 Hz, 2H), 3.77 (q, J=5.49 Hz, 2H).

Workup

  1. stirringwas stirred overnight at room temperature
  2. concentrationAfter this time, the reaction mixture was concentrated in vacuo
  3. customazeotroped with acetonitrile
  4. customThe crude material was then purified by flash column chromatography (silica gel 60, 230-400 mesh, 80% ethyl acetate/hexanes)

Sources & evidence

ORD record
ord-c1b1b977483e4a81956b81bbd006987b
Source dataset
uspto-grants-2013_06
Patent number
US08470866B2

Reaction notes

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