Propargyl bromide → 1-Pyrazolyl propargyl ether

HRID 652695Notes

Reaction equation

HRID 652695 reaction equation
[CH2:1](Br)[C:2]#[CH:3].[OH:5][N:6]1[CH:10]=[CH:9][CH:8]=[N:7]1.C(=O)([O-])[O-].[Na+].[Na+]>C(#N)C.ClCCl>[CH2:1]([O:5][N:6]1[CH:10]=[CH:9][CH:8]=[N:7]1)[C:2]#[CH:3]

Participants

6

Reactant 3

HCID 7842Propargyl bromideHCID 10340Sodium CarbonateHCID 30167331-hydroxy-1H-pyrazole

Product 1

HCID 201962031-Pyrazolyl propargyl etherYield 70%

Reagents, catalysts & solvents 2

HCID 6342AcetonitrileSolventHCID 6344DichloromethaneSolvent

Procedure

21.3 g of propargyl bromide are added to 15 g of 1-hydroxypyrazole and 15 g of sodium carbonate in 200 g of acetonitrile at 25° C., while stirring. Stirring is continued for 12 hours, after which the mixture is filtered under suction, the residue is washed with 100 g of acetonitrile, and the combined liquids are evaporated down in a rotary evaporator at 40° C. and under 20 mbar. The residue obtained in this procedure is dissolved in 200 g of dichloromethane, the solution is extracted 3 times with a total of 200 g of saturated aqueous sodium bicarbonate solution, and the organic phase is dried with magnesium sulfate and evaporated down. 15 g (70% of theory) of 1-pyrazolyl propargyl ether are obtained as an oil (H1 -NMR, δ in ppm: 2.6, t, 1H; 4.9, d, 2H; 6.2, m, 1H; 7.4, m, 2H). This substance is Example 10 in the Table below.

Workup

  1. stirringStirring
  2. filtrationafter which the mixture is filtered under suction
  3. washthe residue is washed with 100 g of acetonitrile
  4. customthe combined liquids are evaporated down in a rotary evaporator at 40° C. and under 20 mbar
  5. customThe residue obtained in this procedure
  6. extractionthe solution is extracted 3 times with a total of 200 g of saturated aqueous sodium bicarbonate solution
  7. dry with materialthe organic phase is dried with magnesium sulfate
  8. customevaporated down

Sources & evidence

ORD record
ord-daa761ab0ee641aeaf146f73c7de9584
Source dataset
uspto-grants-1987_06
Patent number
US04673429

Reaction notes

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