Borane → HCID 22618462, compound

HRID 1078467Notes

Reaction equation

HRID 1078467 reaction equation
[NH2:1][C:2]1[N:6]([C:7]2[C:12]([Cl:13])=[CH:11][C:10]([C:14]([F:17])([F:16])[F:15])=[CH:9][C:8]=2[Cl:18])[N:5]=[C:4]([C:19]([F:22])([F:21])[F:20])[C:3]=1[C:23](O)=O.B.[OH-].[Na+]>O1CCCC1>[NH2:1][C:2]1[N:6]([C:7]2[C:8]([Cl:18])=[CH:9][C:10]([C:14]([F:15])([F:16])[F:17])=[CH:11][C:12]=2[Cl:13])[N:5]=[C:4]([C:19]([F:22])([F:21])[F:20])[C:3]=1[CH3:23]

Participants

5

Reactant 3

HCID 6331Borane2×HCID 14798Sodium HydroxideHCID 14300252HCID 14300252, compound

Product 1

HCID 22618462HCID 22618462, compound

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

To a stirred solution of 5-amino-4-carboxy-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-trifluoromethylpyrazole (15.0 g; hereinbefore described in Reference Example 24) in dry tetrahydrofuran (50 ml) was added, under nitrogen, a solution of boranetetrahydrofuran complex (1 Molar, 27.5 g) during 10 minutes keeping at -20° C. The solution was allowed to reach room temperature and stirred overnight. A further addition of the borane was made (10 ml), and the solution heated under reflux overnight. After cooling, a further addition of the borane (20 ml) was made, and the solution again heated under reflux for 4 hours. After cooling, sodium hydroxide (6N) solution was added to pH 11, and the solution extracted with dichloromethane. The organic phase was washed with water, dried over anhydrous magnesium sulphate, and evaporated in vacuo to give a brown oil. Purification by chromatography on silica (Merck, 40-230 mesh, 0.7 kg cm-2) eluting with hexane-ethyl acetate (2:1) gave 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-4-methyl-3-trifluoromethylpyrazole (2.0 g) from toluene-hexane, m.p. 97°-100° C., in the form of white crystals. ##STR3##

Workup

  1. additionwas added, under nitrogen
  2. customto reach room temperature
  3. temperaturethe solution heated
  4. temperatureunder reflux overnight
  5. temperatureAfter cooling
  6. temperaturethe solution again heated
  7. temperatureunder reflux for 4 hours
  8. temperatureAfter cooling
  9. extractionthe solution extracted with dichloromethane
  10. washThe organic phase was washed with water
  11. dry with materialdried over anhydrous magnesium sulphate
  12. customevaporated in vacuo
  13. customto give a brown oil
  14. customPurification by chromatography on silica (Merck, 40-230 mesh, 0.7 kg cm-2)
  15. washeluting with hexane-ethyl acetate (2:1)

Sources & evidence

ORD record
ord-e5e287350fb04efe8ca537ebab2b83c3
Source dataset
uspto-grants-1996_08
Patent number
US05547974

Reaction notes

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