Diazoethane → 4-(2-Benzoyl-4-chlorophenyl)-3-cyano-5-methylpyrazole

HRID 1701924Notes

Reaction equation

HRID 1701924 reaction equation
[N+:1](=[CH:3][CH3:4])=[N-:2].[C:5]([C:13]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:14]=1[CH:20]=[CH:21][C:22]#[N:23])(=[O:12])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1>CCOCC>[C:5]([C:13]1[CH:18]=[C:17]([Cl:19])[CH:16]=[CH:15][C:14]=1[C:20]1[C:21]([C:22]#[N:23])=[N:2][NH:1][C:3]=1[CH3:4])(=[O:12])[C:6]1[CH:11]=[CH:10][CH:9]=[CH:8][CH:7]=1

Participants

4

Reactant 2

HCID 70695DiazoethaneHCID 543140203-(2-Benzoyl-4-chlorophenyl)prop-2-enenitrile

Product 1

HCID 204537654-(2-Benzoyl-4-chlorophenyl)-3-cyano-5-methylpyrazole

Reagents, catalysts & solvents 1

HCID 3283Diethyl EtherSolvent2×

Procedure

A solution of diazoethane in 400 ml of ether (prepared from 16.1 g (0.1 mol) of N-ethyl-N'-nitro-N-nitrosoimino urea,) was added to a solution of 15 g (0.056 mol) of crude 3-(2-benzoyl-4-chlorophenyl)-2-propenonitrile in 100 ml of ether. After standing at room temperature for 3 hr, the excess diazoethane was destroyed by addition of glacial acetic acid. The mixture was washed with saturated sodium bicarbonate solution, was dried and evaporated, at the end azeotropically with toluene. The residue was dissolved in 400 ml of toluene and the solution was heated to reflux for 11/2 hr in presence of 60 g of activated manganese dioxide. The water was separated in a Dean Stark trap. The MnO2 was removed by filtration over Celite and the filtrate was evaporated. The residue (14 g) was chromatographed over 300 g of silica gel using 10% (v/v) of ethyl acetate in methylene chloride. The homogenous fractions were combined and evaporated to yield an oily product.

Workup

  1. customthe excess diazoethane was destroyed by addition of glacial acetic acid
  2. washThe mixture was washed with saturated sodium bicarbonate solution
  3. customwas dried
  4. customevaporated, at the end azeotropically with toluene
  5. dissolutionThe residue was dissolved in 400 ml of toluene
  6. temperaturethe solution was heated
  7. temperatureto reflux for 11/2 hr in presence of 60 g of activated manganese dioxide
  8. customThe water was separated in a Dean Stark trap
  9. customThe MnO2 was removed by filtration over Celite
  10. customthe filtrate was evaporated
  11. customThe residue (14 g) was chromatographed over 300 g of silica gel using 10% (v/v) of ethyl acetate in methylene chloride
  12. customevaporated
  13. customto yield an oily product

Sources & evidence

ORD record
ord-e52d4bbd8145489593eadf672376667f
Source dataset
uspto-grants-1983_04
Patent number
US04379765

Reaction notes

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