Dimethylformamide → 2-chloro-4-fluoro-5-[4-formyl-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]benzoic acid

HRID 1379810Notes

Reaction equation

HRID 1379810 reaction equation
Br[C:2]1[C:3]([C:12]2[C:13]([F:22])=[CH:14][C:15]([Cl:21])=[C:16]([CH:20]=2)[C:17]([OH:19])=[O:18])=[N:4][N:5]([CH3:11])[C:6]=1[C:7]([F:10])([F:9])[F:8].[H-].[Na+].C([Li])CCC.CN(C)[CH:32]=[O:33]>O1CCCC1>[Cl:21][C:15]1[CH:14]=[C:13]([F:22])[C:12]([C:3]2[C:2]([CH:32]=[O:33])=[C:6]([C:7]([F:10])([F:9])[F:8])[N:5]([CH3:11])[N:4]=2)=[CH:20][C:16]=1[C:17]([OH:19])=[O:18]

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 24758Sodium hydrideHCID 4485645-[4-bromo-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-chloro-4-fluorobenzoic acidHCID 178418339Butyllithium2×

Product 1

HCID 229064152-chloro-4-fluoro-5-[4-formyl-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]benzoic acid

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
60 °C

Procedure

To a mechanically stirred solution of 10 g of 5-[4-bromo-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-chloro-4-fluorobenzoic acid in 400 ml of anhydrous tetrahydrofuran under a nitrogen atmosphere was added 1.0 g of 95% sodium hydride. After the foaming subsided, the reaction was stirred and heated to 60° C. for one hour to ensure complete anion formation of the acid. The reaction was cooled to -110° C. with vigorous stirring and a 10.8 mL of 2.5M n-butyl lithium in hexanes was added maintaining the temperature below -100° C. As soon as the addition of n-butyl lithium was completed, 10 mL of dimethyl formamide was added and the solution was allowed to warm to -20° C. The reaction was then quenched with 3N HCl, and most of the volatiles were removed from the reaction mixture. The precipitate was filtered and recrystalized from carbon tetrachloride to give-3.0 g of 2-chloro-4-fluoro-5-[4-formyl-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]benzoic acid: mp 163° C.; 1HNMR (CDCl3) ppm: 9.82 (s, 1H), 7.89 (d, 1H, J=7.6), 7.07 (d, 1H, J=9.2), 3.39 (s, 3H). 19FNMR (CDCl3) ppm: -57.78, -107.41.

Workup

  1. temperatureThe reaction was cooled to -110° C.
  2. stirringwith vigorous stirring
  3. temperaturemaintaining the temperature below -100° C
  4. temperatureto warm to -20° C
  5. customThe reaction was then quenched with 3N HCl
  6. custommost of the volatiles were removed from the reaction mixture
  7. filtrationThe precipitate was filtered
  8. customrecrystalized from carbon tetrachloride

Sources & evidence

ORD record
ord-42241c0585cb46af8388789ddc86d626
Source dataset
uspto-grants-1997_09
Patent number
US05672715

Reaction notes

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