ChemicalBook CAS DataBase List 4-Fluoro-3-nitrobenzoic acid

4-Fluoro-3-nitrobenzoic acid synthesis

7synthesis methods

Product Name:4-Fluoro-3-nitrobenzoic acid
CAS Number:453-71-4
Molecular formula:C7H4FNO4
Molecular Weight:185.11

456-22-4

453-71-4

General procedure for the synthesis of 4-fluoro-3-nitrobenzoic acid from 4-fluorobenzoic acid: Potassium nitrate (39.7 g, 0.39 mol, 1.1 eq.) was added in batches to a solution of 4-fluorobenzoic acid (50.0 g, 0.36 mol, 1.0 eq.) dissolved in concentrated sulphuric acid (180 ml) under cooling in an ice bath. The reaction mixture was stirred overnight at room temperature and then slowly poured over crushed ice (800 g) under continuous stirring. The resulting mixture was allowed to stand at room temperature overnight, followed by filtration and washing of the solid product with plenty of water. Finally, treatment by azeotropic drying with toluene afforded 59.5 g (90% yield) of 4-fluoro-3-nitrobenzoic acid as a light yellow solid.1H NMR (400 MHz, DMSO-d6): δ 7.69-7.74 (m, 1H), 8.29-8.32 (m, 1H), 8.56 (d, J=7.2 Hz, 1H), 13.75 ( br s, 1H).

456-22-4 Synthesis

456-22-4
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453-71-4
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Yield:453-71-4 90%

Reaction Conditions:

with sulfuric acid;potassium nitrate at 20;

Steps:

1.1

To a cold solution of 4-fluorobenzoic acid (50.0 g, 0.36 mol, 1.0 equiv) in concentrated H₂SO₄(180 ml) was added portionwise potassium nitrate (39.7 g, 0.39 mol, 1.1 equiv). The reaction mixture was stirred overnight at rt and then poured on crushed ice (800 g) with constant stirring. The resulting mixture was kept overnight at rt, filtered and washed thoroughly with water, and finally dried by making an azeotrope with toluene to yield 59.5 g (90%) of the title compound as a light yellow solid. ¹H NMR (400 MHz, DMSO): δ 7.69-7.74 (m, 1H), 8.29-8.32 (m, 1H), 8.56 (d, J=7.2 Hz, 1H), 13.75 (br s, 1H).

References:

US2008/249101,2008,A1 Location in patent:Page/Page column 20

1009-35-4 Synthesis