3-Bromo-4-fluorobenzenamine

light yellow crystal

In a 2 L four-necked round bottom flask equipped with a stirrer, an Erlin condenser, a 1 L dropping funnel and a thermometer, 466.9 g (2.07 mol) of tin chloride dihydrate and 760 mL of ethanol, and the mixture was stirred at room temperature. Then, in a state where tin chloride was completely dissolved, a THF solution (760 mL) of 102.7 g (0.466 mol) of 3-bromo-4-fluoronitrobenzene was added dropwise, followed by stirring at 60 ° C. for 2 hours. Once the reaction solution obtained was once cooled to room temperature, the solvent was distilled off under reduced pressure, 440 g of ice was added to the obtained residue, and the mixture was made alkaline with 1580 mL of a 7percent sodium hydroxide aqueous solution. The resultant slurry was separated by suction filtration, and the residue on the nutsche was rinsed with 600 mL of DCM. Then, the organic layer of the recovered filtrate was separated and the aqueous layer was extracted with 600 mL of DCM. Next, the DCM layers were combined into one, washed with 600 mL of water, dried using potassium carbonate, and the potassium carbonate was removed by suction filtration and the solvent was distilled off under reduced pressure. Subsequently, the obtained crude product was purified by silica gel column chromatography using toluene as a developing solvent to obtain 54.7 g (yield 61.7percent) of the objective compound.Sodium chlorite (6.78 g, 75 mmol) and 4-fluoro-3-bromobenzaldehyde (24.63 mmol) were dissolved in 1: 1 THF/water (100 mL) and stirred vigorously at 50 oC for 5 h. EtOAc (250 mL) and IN HC1 (50 mL) was added and the layers were separated. The organic layer was washed with water (3 x 50 mL), then was extracted with 0. 5M NA2CO3 (10 x 50 mL). The combined basic aqueous layers were slowly acidified with concentrated HC1 while stirring, to precipitate the carboxylic acid product. The solid was collected via filtration and dried under high vacuum overnight (4.93 g, 91percent). A portion of the solid carboxylic acid was dissolved in chloroform (30 mL) and concentrated sulfuric acid was added. A reflux condenser was attached to the flask and the solution was heated to 55 oC. Sodium azide (2.36 g, 36.45 mmol) was added in 3 portions over 1 h. After 4 h, additional sulfuric acid (10 mL) and sodium azide (1 g) were added and the reaction was stirred at 55 oC for 16 h. The mixture was transferred to a large cooled flask and the sulfuric acid was slowly quenched with 5N sodium hydroxide. The solution was adjusted to PH-8 and the aqueous solution was extracted with DCM (5 x 30 mL). The organic extracts were dried over sodium sulfate and concentrated in vacuo to yield a dark brown oil (2.2 g, 95percent) that solidified upon standing. 1H-NMR (CDC13): δ 6.94 (t, 8.4 Hz), 6.88 (dd, 1H, J = 2.8, 5.6 Hz), 6.58 (m, 1H), 3.62 (s, 2H).a

Used as medicine and pesticide intermediate

Molecular Weight:190.01
XLogP3:2.1
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Exact Mass:188.95894
Monoisotopic Mass:188.95894
Topological Polar Surface Area:26
Heavy Atom Count:9
Complexity:99.1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes