Hydrazine hydrate (1:1) → 5-(3-methylbutyl)-1H-pyrazole-3-carboxylic Acid Ethyl Ester

HRID 1724756Notes

Reaction equation

HRID 1724756 reaction equation
O.[NH2:2][NH2:3].[CH2:4]([O:6][C:7](=[O:18])[C:8](=O)[CH2:9][C:10](=O)[CH2:11][CH2:12][CH:13]([CH3:15])[CH3:14])[CH3:5]>CCO>[CH2:4]([O:6][C:7]([C:8]1[CH:9]=[C:10]([CH2:11][CH2:12][CH:13]([CH3:15])[CH3:14])[NH:3][N:2]=1)=[O:18])[CH3:5]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 574350907-Methyl-2,4-dioxooctanoic acid ethyl ester

Product 1

HCID 574350915-(3-methylbutyl)-1H-pyrazole-3-carboxylic Acid Ethyl EsterYield 707.9%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Hydrazine hydrate (1.43 mL, 2.95 mmol) was added to a stirring room temperature solution of 46 (6.3112 g, 2.95 mmol) in EtOH (29.5 mL, 1 M) under N2. The reaction was then stirred at room temperature until judged complete by HPLC (35 min): The reaction was concentrated and purified by silica gel chromatography (Combiflash column, 96:4 Hexanes: 2N NH3 in EtOH): Only pure fractions were combined and concentrated to obtain 4.3911 g (70.9%) of 47. 1H (CDCl3, 400 MHz): δ 13.01 (1H, broad s), 6.52 (1H, s), 4.29 (2H, q, J=7.1 Hz), 2.64 (2H, t, J=7.8 Hz), 1.57-1.41 (3H, m), 1.26 (3H, t, J=7.1 Hz), 5.85 (6H, d, J=5.9 Hz) ppm. 13C (CDCl3, 100 MHz): δ 162.37, 146.26, 143.1, 105.73, 60.53, 37.88, 27.35, 23.42, 22.11, 14.06 ppm. HPLC: 10.006 min.

Workup

  1. customuntil judged complete by HPLC (35 min)
  2. concentrationThe reaction was concentrated
  3. custompurified by silica gel chromatography (Combiflash column, 96:4 Hexanes: 2N NH3 in EtOH)
  4. concentrationconcentrated

Sources & evidence

ORD record
ord-35bfee26c33a4c17965df7c36f17e3ad
Source dataset
uspto-grants-2009_02
Patent number
US07488747B2

Reaction notes

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