Borane → HCID 22618462, compound

HRID 2253795Notes

Reaction equation

HRID 2253795 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 (6 N) 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-6c423ed3cb1044e1af389a39782e4323
Source dataset
uspto-grants-1993_08
Patent number
US05232940

Reaction notes

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