1-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-3-nitro-1H-pyrazole → 1-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-1H-pyrazol-3-ylamine

HRID 1772133Notes

Reaction equation

HRID 1772133 reaction equation
[Si:1]([O:8][CH2:9][CH2:10][N:11]1[CH:15]=[CH:14][C:13]([N+:16]([O-])=O)=[N:12]1)([C:4]([CH3:7])([CH3:6])[CH3:5])([CH3:3])[CH3:2]>C(O)C>[Si:1]([O:8][CH2:9][CH2:10][N:11]1[CH:15]=[CH:14][C:13]([NH2:16])=[N:12]1)([C:4]([CH3:7])([CH3:5])[CH3:6])([CH3:3])[CH3:2]

Participants

3

Reactant 1

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

Product 1

HCID 593449471-[2-(tert-butyl-dimethyl-silanyloxy)-ethyl]-1H-pyrazol-3-ylamineYield 102.2%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A 250-mL Parr reactor bottle was purged with nitrogen and charged with 10% palladium on carbon (50% wet, 150 mg dry weight) and a solution of 119a (1.02 g, 3.76 mmol) in ethanol (20 mL). The bottle was attached to a Parr hydrogenator, evacuated, charged with hydrogen gas to a pressure of 50 psi and shaken for 3 h. After this time, the hydrogen was evacuated, and nitrogen was charged into the bottle. Celite 521 (1.00 g) was added, and the mixture was filtered through a pad of Celite 521. The filter cake was washed with ethanol (2×25 mL), and the combined filtrates were concentrated to dryness under reduced pressure to afford a 100% yield (928 mg) of 119b as a white solid: mp 54-55° C.; 1H NMR (500 MHz, CDCl3) δ 7.25 (d, 1H, J=2.0 Hz), 5.36 (d, 1H, J=2.0 Hz), 4.54 (br s, 2H), 3.90 (t, 2H, J=5.5 Hz), 3.81 (t, 2H, J=5.5 Hz), 0.84 (s, 9H), −0.35 (s, 6H). MS (APCI+) m/z 242.6 (M+H).

Workup

  1. customA 250-mL Parr reactor bottle was purged with nitrogen
  2. additioncharged with 10% palladium on carbon (50% wet, 150 mg dry weight)
  3. customevacuated
  4. additioncharged with hydrogen gas to a pressure of 50 psi
  5. customAfter this time, the hydrogen was evacuated
  6. additionnitrogen was charged into the bottle
  7. additionCelite 521 (1.00 g) was added
  8. filtrationthe mixture was filtered through a pad of Celite 521
  9. washThe filter cake was washed with ethanol (2×25 mL)
  10. concentrationthe combined filtrates were concentrated to dryness under reduced pressure

Sources & evidence

ORD record
ord-af35eac8d6a241b69484833236bc87c1
Source dataset
uspto-grants-2016_02
Patent number
US09249123B2

Reaction notes

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