2,3,5,6-Tetrafluoroaniline

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:0.00; pressure:0.00; stir:

Conditions: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3,5,6-Tetrafluoroaniline was produced from 4-amino-2,3,5,6-tetrafluorobenzonitrile. To be specific, in a 200 ml four-neck flask provided with a stirrer, a thermometer, a dropping funnel, and a water separating tube, 100 g of 60% sulfuric acid was placed and heated to 140° C. To the hot sulfuric acid, 36 g of the raw material, 4-amino-2,3,5,6-tetrafluorobenzonitrile (having a purity of 94% and containing 6% of 2-amino-3,4,5,6-tetrafluorobenzonitrile as an impurity) was added dropwise at a rate of 6 g/hr. The 2,3,5,6-tetrafluoroaniline which was formed by the reaction was expelled by azeotropy with water, guided into the water dropping tube, and separated from the water. The reaction was continued for six hours while the reaction vessel was supplied with the same amount of water as expelled by distillation. After the completion of the reaction, the conversion ratio of the raw material determined by gas chromatography was found to be 96 mol %. When the 2,3,5,6-tetrafluoroaniline expelled by distillation was analyzed, the purity was found to be 95.3% and the yield to be 82.5%. To be specific, in a 200 ml four-neck flask provided with a stirrer was added dropwise at a rate of 6 g/hr

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2,3,5,6-tetrafluoroaniline (4.5 g, 27.3 mmol), 4-ethylbromobenzene (5.0 g, 27 mmol), toluene (50 ml), sodium tert-butoxide (4.67 g, 48 mmol), tri-tert-butylphosphin (217 mg, 1.07 mmol) and bis-dibenzylideneacetone-palladium(0) (260 mg, 0.45 mmol) is heated under nitrogen to 85° C. for 15.5 h. The mixture is cooled to room temperature and water (30 ml), concentrated hydrochloric acid (20 ml) and hyflo are added. After stirring for 45 minutes, the mixture is filtered and the organic phase is washed with water three times. The solvent is evaporated in vacuo and the residue is chromatographed on silica using hexane/toluene (9:1 to 3:1) affording N-(2′,3′,5′,6′-tetrafluorophenyl)-4-ethylanilin as a liquid. The mixture is cooled to room temperature the mixture is filtered the organic phase is washed with water three times The solvent is evaporated in vacuo the residue is chromatographed on silica

Conditions: temp:0.00; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3,5,6-Tetrafluoroaniline (25.0 g, 0.15 mol) is dissolved in methanol (100 mL) and treated with elemental bromine (28.4 g, 0.17 mol) by dropwise addition at room temperature. Solid sodium bicarbonate (15 g, 0.18 mol) is added portionwise and the resulting mixture stirred for an additional 2 hours. The reaction mixture is partitioned between Et2O (500 mL) and water (1000 mL). The organic layer is dried (MgSO4) and evaporated by a rotary evaporator to give 2,3,5,6-tetrafluoro-4-bromoaniline (m.p. 59–60° C.). The reaction mixture is partitioned between Et2O (500 mL) and water (1000 mL) The organic layer is dried (MgSO4) evaporated by a rotary evaporator

Conditions: temp:140.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: 2,3,5,6-Tetrafluoroaniline was produced from 4-amino-2,3,5,6-tetrafluorobenzonitrile. To be specific, in a 200 ml four-neck flask provided with a stirrer, a thermometer, a dropping funnel, and a water separating tube, 100 g of 60% sulfuric acid was placed and heated to 140° C. To the hot sulfuric acid, 36 g of the raw material, 4-amino-2,3,5,6-tetrafluorobenzonitrile (having a purity of 94% and containing 6% of 2-amino-3,4,5,6-tetrafluorobenzonitrile as an impurity) was added dropwise at a rate of 6 g/hr. The 2,3,5,6-tetrafluoroaniline which was formed by the reaction was expelled by azeotropy with water, guided into the water dropping tube, and separated from the water. The reaction was continued for six hours while the reaction vessel was supplied with the same amount of water as expelled by distillation. After the completion of the reaction, the conversion ratio of the raw material determined by gas chromatography was found to be 96 mol %. When the 2,3,5,6-tetrafluoroaniline expelled by distillation was analyzed, the purity was found to be 95.3% and the yield to be 82.5%. To be specific, in a 200 ml four-neck flask provided with a stirrer was added dropwise at a rate of 6 g/hr

Conditions: temp:85.01; pressure:0.00; stir:; See reaction.notes.procedure_details.

Procedure: A mixture of 2,3,5,6-tetrafluoroaniline (4.5 g, 27.3 mmol), 4-ethylbromobenzene (5.0 g, 27 mmol), toluene (50 ml), sodium tert-butoxide (4.67 g, 48 mmol), tri-tert-butylphosphin (217 mg, 1.07 mmol) and bis-dibenzylideneacetone-palladium(0) (260 mg, 0.45 mmol) is heated under nitrogen to 85° C. for 15.5 h. The mixture is cooled to room temperature and water (30 ml), concentrated hydrochloric acid (20 ml) and hyflo are added. After stirring for 45 minutes, the mixture is filtered and the organic phase is washed with water three times. The solvent is evaporated in vacuo and the residue is chromatographed on silica using hexane/toluene (9:1 to 3:1) affording N-(2′,3′,5′,6′-tetrafluorophenyl)-4-ethylanilin as a liquid. The mixture is cooled to room temperature the mixture is filtered the organic phase is washed with water three times The solvent is evaporated in vacuo the residue is chromatographed on silica