Nitric Acid → 2-Bromo-3-fluoro-6-nitrobenzoic acid

HRID 471606

Reaction equation

[Br:1][C:2]1[C:10]([F:11])=[CH:9][CH:8]=[CH:7][C:3]=1[C:4]([OH:6])=[O:5].[N+:12]([O-])([OH:14])=[O:13]>OS(O)(=O)=O>[Br:1][C:2]1[C:10]([F:11])=[CH:9][CH:8]=[C:7]([N+:12]([O-:14])=[O:13])[C:3]=1[C:4]([OH:6])=[O:5]

Participants

Conditions

Temperature: 0 °C

Procedure

In a 1 L, three necked flask fitted with a dropping funnel and a thermometer were charged 2-bromo-3-fluorobenzoic acid (Example 134 g) (28.23 g, 0.13 mol) and concentrated H2SO4 (200 mL). After cooling to 0° C., HNO3 (70%, 16.0 mL) was added dropwise over 30 min, keeping the temperature between 0 to 10° C. After 1 h, the reaction mixture was poured into the crushed ice keeping the temperature below 20° C. The mixture was extracted with EtOAc (2×200 mL), the combined extract was washed with brine and dried with MgSO4. The filtrate was evaporated to give 27.27 g (77%) of a mixture of 2-bromo-3-fluoro-6-nitrobenzoic acid and 2-bromo-3-fluoro-5-nitrobenzoic acid (1:0.4) as a brown solid. 1H NMR (400 MHz, DMSO-d6) δ 8.33 (dd, J=9.6, 4.8 Hz, 1H), 7.21 (dd, J=10.0, 8.0 Hz, 1H).

Workup

customIn a 1 L, three necked flask fitted with a dropping funnel
custombetween 0 to 10° C
extractionThe mixture was extracted with EtOAc (2×200 mL)
extractionthe combined extract
washwas washed with brine
dry with materialdried with MgSO4
customThe filtrate was evaporated

Sources & evidence

ORD record: ord-3ff681a966ba4954afdbf48c5fed65a2
Source dataset: uspto-grants-2014_01
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US08633186B2

Linked notes

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