tert-Butylhydrazine monohydrochloride → 1,1-Dimethylethyl 4-[1-(1,1-dimethylethyl)-3-methyl-1H-pyrazol-5-yl]-1-piperazinecarboxylate

HRID 1829135Notes

Reaction equation

HRID 1829135 reaction equation
[C:1]([N:7]1[CH2:12][CH2:11][N:10]([C:13]([O:15][C:16]([CH3:19])([CH3:18])[CH3:17])=[O:14])[CH2:9][CH2:8]1)(=O)[CH2:2][C:3]([CH3:5])=O.Cl.Cl.Cl.CC1C=C(N2CCN([C@@H]3CN[C@H](C(N4CCSC4)=O)C3)CC2)N(C2C=CC=CC=2)N=1.Cl.[C:54]([NH:58][NH2:59])([CH3:57])([CH3:56])[CH3:55]>C(O)C>[C:16]([O:15][C:13]([N:10]1[CH2:11][CH2:12][N:7]([C:1]2[N:58]([C:54]([CH3:57])([CH3:56])[CH3:55])[N:59]=[C:3]([CH3:5])[CH:2]=2)[CH2:8][CH2:9]1)=[O:14])([CH3:19])([CH3:18])[CH3:17]

Participants

5

Reactant 3

HCID 81889tert-Butylhydrazine monohydrochlorideHCID 22028659HCID 22028659, compoundHCID 67507852HCID 67507852, compound

Product 1

HCID 220289911,1-Dimethylethyl 4-[1-(1,1-dimethylethyl)-3-methyl-1H-pyrazol-5-yl]-1-piperazinecarboxylateYield 18.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

1-Acetoacetyl-4-tert-butoxycarbonylpiperazine [product of Example 222 (1), 3.92 g] was dissolved in ethanol (300 mL), and tert-butylhydrazine hydrochloride (1.81 g) and molecular sieves 3A (10 g) were added thereto at room temperature. The mixture was stirred for 15 hr. The reaction mixture was filtrated and the filtrate was concentrated under reduced pressure. The residue was dissolved in pyridine (200 mL), and phosphorus oxychloride (3.0 mL) was added thereto at room temperature. The mixture was stirred for 24 hr. The reaction mixture was concentrated under reduced pressure, the residue was acidified with dilute hydrochloric acid to pH 3. The mixture was extracted with ethyl acetate. The extract was washed successively with saturated aqueous sodium hydrogencarbonate solution and brine and dried. The solvent was evaporated under reduced pressure and the residue was purified by silica gel chromatography to give 1-tert-butoxycarbonyl-4-(1-tert-butyl-3-methyl-5-pyrazolyl)piperazine (886 mg) as an oil.

Workup

  1. customat room temperature
  2. filtrationThe reaction mixture was filtrated
  3. concentrationthe filtrate was concentrated under reduced pressure
  4. dissolutionThe residue was dissolved in pyridine (200 mL)
  5. additionphosphorus oxychloride (3.0 mL) was added
  6. customat room temperature
  7. stirringThe mixture was stirred for 24 hr
  8. concentrationThe reaction mixture was concentrated under reduced pressure
  9. extractionThe mixture was extracted with ethyl acetate
  10. washThe extract was washed successively with saturated aqueous sodium hydrogencarbonate solution and brine
  11. customdried
  12. customThe solvent was evaporated under reduced pressure
  13. customthe residue was purified by silica gel chromatography

Sources & evidence

ORD record
ord-017b37805e5c4fb29dbc5b53347e14ef
Source dataset
uspto-grants-2006_06
Patent number
US07060722B2

Reaction notes

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