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

HRID 1488746Notes

Reaction equation

HRID 1488746 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) δ1.36 (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-88e6d190307f4796ad67e811d8e5b2e3
Source dataset
uspto-grants-1997_10
Patent number
US05675017

Reaction notes

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