2-Chloro-4-bromobenzaldehyde

Light yellow crystalline powder

Compound 44; Oxalylchloride (6.9 g, 54 mmol, 1.3 equiv.) was dissolved in DCM (153 ml) and cooled to -78 4-bromo-2-chlorobenzaldehyde. A mixture of (4-bromo-3-chlorophenyl)methanol (2.0 g, 9.0 mmol), pyridinium chlorochromate (2912 mg, 13.5 mmol) in dichloromethane (50 mLO was stirred at 25°C for 3 hours. The mixture was concentrated to give a residue. The residue was purified by column chromatography (silica gel, petroleum ethe/ ethyl acetate = 1 : 1) to give (4-bromo-2-chlorophenyl)methanol as a white solid (4.12g g, 81percent). 1H NMR (300 MHz, dA mixture of (4-bromo-3-chlorophenyl)methanol (2.0 g, 9.0 mmol), pyridinium chlorochromate (2912 mg, 13.5 mmol) in dichloromethane (50 mL0 was stirred at 25° C. for 3 hours. The mixture was concentrated to give a residue. The residue was purified by column chromatography (silica gel, petroleum ethe/ethyl acetate=1:1) to give (4-bromo-2-chlorophenyl)methanol as a white solid (4.12 g g, 81percent). To a solution of (4-bromo-2-chlorophenyl)methanol (2.8 g, 12.8 mmol) that was obtained in Example 24 (24e) in dichloromethane (50 ml) was added pyridinium dichromate (7.2 g, 19.2 mmol) with stirring, and the resulting mixture was stirred at room temperature for 1 hour. After stirring, ether (250 ml) was added to the reaction mixture under stirring, and the resulting mixture was filtered with Celite. The filtrate was evaporated in vacuo, and the crude product of the title compound thus obtained was purified by chromatography on a silica gel column using a mixed solvent of ethyl acetate and hexane (1:20) as the eluent to afford the title compound (2.0 g, yield: 70 percent) as a white crystalline solid. A solution of A- bromo-2-chloro-l-(dibromomethyl)benzene (17.7 g, 48.7 mmol) in ethanol (25 mL) was stirred and heated to reflux, and a solution of silver(I) nitrate (77.4 g, 456 mmol) in water (55 mL) was added dropwise over 20 minutes. The mixture turned yellow and a precipitate of silver bromide formed immediately upon addition. Following completion of addition, the mixture was stirred at reflux for an additional hour. After cooling to ambient temperature, the b) Preparation of 4-bromo-2-chlorobenzaldehvde To a stirring solution of 4-bromo-2-chloro-1-iodo-benzene (10 g, 31.6 mmol) in tetrahydrofuran (100 mL) at -70 °C was added dropwise a solution of isopropylmagnesium chloride (17.4 mL, 34.6 mmol, 2.0 M in tetrahydrofuran), keeping the internal temperature below -60 °C. Ten minutes after the addition was complete, anhydrous N, N-dimethylformamide (7.4 mL, 47.4 mmol) was added rapidly and the reaction mixture was allowed to warm to ambient temperature. After one hour at ambient temperature, the reaction was quenched with saturated aqueous ammonium chloride (50 mL) and the mixture was extracted with ethyl acetate (100 mL). The organic layer was concentrated at reduced pressure and triturated with hexanes (50 mL), cooled to 0 °C and filtered to give the product. The filtrate was purified by silica gel chromatography (12 g cartridge) eluting with ethyl acetate/hexanes (1:9) to give additional product as a white solid (4.65 g, 67percent). General procedure: In a 10-mL round-bottom flask equipped with a magnetic stirring bar, 1 mM of the 2-nitrophenol was reacted with different amounts of the oxidant, acid, bromide source, and the vanadyl Schiff base complex in 4 mL of solvent. The content was stirred at room temperature.The progress of the reaction was monitored by GLC.(2) 4-bromo-2-chloro -N- methoxy -N- methylbenzamide (6.09 g)Of tetrahydrofuran (40mL)In solution, under ice-cooling lithium aluminum hydride (975mg)It was stirred for 1 hour in addition.The temperature was raised to room temperature by the addition of 1M hydrochloric acid to the reaction solution, and extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, after filtration, concentrated under reduced pressure. The obtained residue was purified by silica gel column chromatography (hexane: ethyl acetate = 95: 5 → 80: 20) to afford 4-bromo-2-chloro benzaldehyde (4.05 g) as a colorless solid.

Molecular Weight:219.46
XLogP3:2.7
Hydrogen Bond Acceptor Count:1
Rotatable Bond Count:1
Exact Mass:217.91341
Monoisotopic Mass:217.91341
Topological Polar Surface Area:17.1
Heavy Atom Count:10
Complexity:129
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes