Hydrochloric Acid → 2,6-Difluoro-4-nitrobenzoic acid

HRID 634684Notes

Reaction equation

[OH-:1].[Na+].Cl[CH:4]([C:10]1[C:15]([F:16])=[CH:14][C:13]([N+:17]([O-:19])=[O:18])=[CH:12][C:11]=1[F:20])C(OCC)=O.[OH:21]O.S([O-])([O-])=O.[Na+].[Na+].Cl>C(O)C>[F:20][C:11]1[CH:12]=[C:13]([N+:17]([O-:19])=[O:18])[CH:14]=[C:15]([F:16])[C:10]=1[C:4]([OH:21])=[O:1]

Participants

Conditions

Temperature: 18 °C

Procedure

2.5M Aqueous sodium hydroxide solution (300 ml) was added over 5 minutes to a solution of ethyl 2-chloro-2-(2,6-difluoro-4-nitrophenyl)ethanoate (34.86 g 125 mmol) in ethanol (300 ml) at 5° C. such that the reaction temperature was kept below 25° C. The mixture was cooled to 18° C. and 30% hydrogen peroxide (40 ml) was added. The mixture was stirred at 20° C. for 2.5 hours. Sodium sulphite was added until the peroxide test was negative, the mixture was acidified to pH1 with 6M hydrochloric acid and extracted with ethyl acetate. The organic extracts were back extracted with saturated aqueous sodium hydrogen carbonate solution, the aqueous extracts were acidified with concentrated hydrochloric acid and extracted with ethyl acetate. The extracts were dried (MgSO4) and the solvent removed by evaporation to give 2,6-difluoro-4-nitrobenzoic acid (4.89 g, 19%).

Workup

customwas kept below 25° C
extractionextracted with ethyl acetate
extractionThe organic extracts were back extracted with saturated aqueous sodium hydrogen carbonate solution
extractionextracted with ethyl acetate
dry with materialThe extracts were dried (MgSO4)
customthe solvent removed by evaporation

Sources & evidence

ORD record: ord-3fee34152a3a45baa7678f8bb98114c8
Source dataset: uspto-grants-2001_02
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US06184225B2

Reaction notes

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