Ethylhydrazine → 1,3-Diethyl-5-methylpyrazole

HRID 1245585Notes

Reaction equation

HRID 1245585 reaction equation
[CH3:1][CH2:2][C:3](=O)[C:4]#[C:5][CH3:6].[CH2:8]([NH:10][NH2:11])[CH3:9]>C(O)CCC.O>[CH2:8]([N:10]1[C:5]([CH3:6])=[CH:4][C:3]([CH2:2][CH3:1])=[N:11]1)[CH3:9]

Participants

5

Reactant 2

HCID 29062EthylhydrazineHCID 139192Hex-4-yn-3-one

Product 1

HCID 219127841,3-Diethyl-5-methylpyrazole

Reagents, catalysts & solvents 2

HCID 2631-ButanolSolventHCID 962WaterSolvent

Procedure

A solution of 18.9 g (0.2 mol) of hex-4-yn-3-one (from Step B) in 120 mL of n-butanol was treated with 40 mL (0.227 mol) of ethyl hydrazine, 34% solution in water. The resulting mixture was heated at reflux for 1.5 h, then cooled to rt. The mixture was concentrated to ˜150 μL volume; this was partitioned between 1 L of ether and 250 mL of water. The layers were separated and the organic layer was dried and concentrated to afford the title compound, which was used without further purification. 1H-NMR (400 MHz) δ 1.22 (t, J=7.6, 3H), 1.37 (t, J=7.2, 3H), 2.23 (s, 3H), 2.59 (q, J=7.6, 2H), 4.01 (q, J=7.2, 2H), 5.81 (s, 1H).

Workup

  1. temperatureThe resulting mixture was heated
  2. temperatureat reflux for 1.5 h
  3. concentrationThe mixture was concentrated to ˜150 μL volume
  4. customthis was partitioned between 1 L of ether and 250 mL of water
  5. customThe layers were separated
  6. customthe organic layer was dried
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-dfafc93cd2f74f92b26a72a46b9d3642
Source dataset
uspto-grants-2006_10
Patent number
US07125887B2

Reaction notes

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