Hydrazine hydrate (1:1) → (3,5-diethyl-1H-pyrazol-4-yl)acetic acid ethyl ester

HRID 220459Notes

Reaction equation

HRID 220459 reaction equation
[CH2:1]([O:3][C:4](=[O:15])[CH2:5][CH:6]([C:11](=O)[CH2:12][CH3:13])[C:7](=O)[CH2:8][CH3:9])[CH3:2].O.[NH2:17][NH2:18]>C(O)(=O)C>[CH2:1]([O:3][C:4](=[O:15])[CH2:5][C:6]1[C:11]([CH2:12][CH3:13])=[N:17][NH:18][C:7]=1[CH2:8][CH3:9])[CH3:2]

Participants

4

Reactant 2

HCID 24654Hydrazine hydrate (1:1)HCID 50988004Ethyl 4-oxo-3-propanoylhexanoate

Product 1

HCID 57899303(3,5-diethyl-1H-pyrazol-4-yl)acetic acid ethyl esterYield 98.4%

Reagents, catalysts & solvents 1

HCID 176Acetic AcidSolvent

Procedure

Combine 4-oxo-3-propionylhexanoic acid ethyl ester (2.49 g, 11.6 mmol) and hydrazine hydrate (0.70 g, 13.9 mmol) in glacial acetic acid (20 mL) and stir at room temperature for 88 hr. Concentrate to an oil. Partition this residue between ethyl acetate (100 mL) and saturated aqueous sodium bicarbonate solution (50 mL). Separate the organic layer; dry (sodium sulfate), filter and concentrate to provide (3,5-diethyl-1H-pyrazol-4-yl)-acetic acid ethyl ester (2.4 g, 98%). 1H-NMR (400 MHz, CDCl3) δ 8.64 (bs, 1H), 4.08 (q, 2H), 3.35 (s, 2H), 2.61 (q, 4H), 1.21 (m, 9H).

Workup

  1. concentrationConcentrate to an oil
  2. customPartition this residue between ethyl acetate (100 mL) and saturated aqueous sodium bicarbonate solution (50 mL)
  3. customSeparate the organic layer
  4. dry with materialdry (sodium sulfate)
  5. filtrationfilter
  6. concentrationconcentrate

Sources & evidence

ORD record
ord-38c32f20f2b7499ba049fdbef6490742
Source dataset
uspto-grants-2012_06
Patent number
US08202873B2

Reaction notes

Loading…