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

HRID 1378301Notes

Reaction equation

[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([C:12]2[C:16]([CH:17]=[O:18])=[C:15]([C:19]([F:22])([F:21])[F:20])[N:14]([CH3:23])[N:13]=2)=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[C:24](Cl)(=O)[C:25](Cl)=O.[CH3:30]N(C=O)C>C(Cl)Cl.CC(O)C>[Cl:1][C:2]1[CH:10]=[C:9]([F:11])[C:8]([C:12]2[C:16]([CH:17]=[O:18])=[C:15]([C:19]([F:20])([F:21])[F:22])[N:14]([CH3:23])[N:13]=2)=[CH:7][C:3]=1[C:4]([O:6][CH:24]([CH3:25])[CH3:30])=[O:5]

Participants

Conditions

Temperature: 50 °C

Procedure

To a slurry of 2.5 g of 2-chloro-4-fluoro-5-[4-formyl-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]benzoic acid (Ex. 3) in 50 ml of methylene chloride was added 10 mL of oxalyl chloride followed by catalytic DMF. The solution was stirred for one hour and concd in vacuo. The resultant residue was diluted in 2-propanol and heated to 50° C. for one hour. The reaction was poured onto water and extracted into diethyl ether. The combined organic extracts were washed with brine and 2.5N sodium hydroxide solution, dried and concd to give a material which contained the desired product and a bi-product. Chromatographic purification (silica, 10% ethyl acetate in hexanes) afforded 1.0 g of 2-chloro-4-fluoro-5-[4-formyl-1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]benzoic acid, 1-methylethyl ester in a 36% yield: mp 90° C.; 1HNMR (CDCl3) δ 10.04 (s, 1H), 7.9 (d, 1H, J=7.6), 7.25 (d, 1H, J=9.2), 5.23 (m, 1H), 4.11 (s, 3H), 1.35 (d, 6H, J=6.0).

Workup

additionThe reaction was poured onto water
extractionextracted into diethyl ether
washThe combined organic extracts were washed with brine and 2.5N sodium hydroxide solution
customdried
customto give a material which

Sources & evidence

ORD record: ord-c28a3588a2fa42b8a0f8475a5073b4f1
Source dataset: uspto-grants-1997_09
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US05668088

Reaction notes

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