Dichloromethane → 2-chloro-5-[1,4-dimethyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-4-fluorobenzoic acid, 1-methylethyl ester

HRID 1378298Notes

Reaction equation

HRID 1378298 reaction equation
[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([C:12]2[C:16]([CH3:17])=[C:15]([C:18]([F:21])([F:20])[F:19])[N:14]([CH3:22])[N:13]=2)=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:23](Cl)(=O)[C:24](Cl)=O.[CH2:29](Cl)Cl>CN(C=O)C.CC(O)C.CCOCC>[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([C:12]2[C:16]([CH3:17])=[C:15]([C:18]([F:19])([F:20])[F:21])[N:14]([CH3:22])[N:13]=2)=[CH:7][C:3]=1[C:4]([O:6][CH:23]([CH3:24])[CH3:29])=[O:5]

Participants

7

Reactant 3

HCID 6344DichloromethaneHCID 65578Oxalyl chlorideHCID 229064292-Chloro-5-[1,4-dimethyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-4-fluorobenzoic acid

Product 1

HCID 570191292-chloro-5-[1,4-dimethyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-4-fluorobenzoic acid, 1-methylethyl ester

Reagents, catalysts & solvents 3

HCID 6228DimethylformamideCatalystHCID 3283Diethyl EtherSolventHCID 3776IsopropanolSolvent

Procedure

To a solution of 18 g of 2-chloro-5-[1,4-dimethyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-4-fluorobenzoic acid. (Ex. 2) in 400 mL of CH2Cl2 was added 10 g of oxalyl chloride and a few drops of DMF. After 20 minutes at room temperature, the reaction was heated to reflux for 2 hr and subsequently concd in vacuo. The resultant solid was dissolved in excess 2-propanol and heated overnight at reflux. The reaction mixture was concd, dissolved in ether, washed with 10% aq. NaOH and saturated brine and concd to give a solid. Recrystallization from cold hexanes gave 14 g of 2-chloro-5-[1,4-dimethyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-4-fluorobenzoic acid, 1-methylethyl ester: mp 72° C.; 1HNMR (CDCl3) δ 1.36 (d, 6H, 6.4 Hz), 2.09 (quintet, 3H, 2.0 Hz), 5.25 (heptet, 1H, 6.0 Hz), 7.27 (d, 1H, 9.2 Hz), 7.94 (d, 1H, 7.6 Hz). Anal. Calcd for C16H15O2N2F4Cl: C, 50.74; H, 3.99; N, 7.40. Found: C, 50.85; H, 4.02; N, 7.41.

Workup

  1. temperaturethe reaction was heated
  2. temperatureto reflux for 2 hr
  3. temperatureheated overnight
  4. temperatureat reflux
  5. washwashed with 10% aq. NaOH and saturated brine and concd
  6. customto give a solid
  7. customRecrystallization from cold hexanes

Sources & evidence

ORD record
ord-358172ab649540f5b96682d5a935cd27
Source dataset
uspto-grants-1997_09
Patent number
US05668088

Reaction notes

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