3-BROMO-2-HYDROXY-5-NITROBENZALDEHYDE

2-Hydroxy-5-nitro-benzaldehyde (2.0 g, 12 mmol) and dichloromethane (30 mL) were added to a 100 mL two-neck flask, then bromine (2.24 g, 14 mmol) was added dropwise. The mixture was stirred for 1 h at rt. The mixture was quenched with saturated aqueous sodium thiosulfate (100 mL), and the resulting mixture was partitioned. The aqueous phase was extracted with ethyl acetate (100 mL x 2). The combined organic phases were washed with saturated brine (80 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, the residue was purified by silica gel chromatography (ethyl acetate/petroleum ether (v/v) = 1/20) to give the title compound as a yellow solid (2.89 g, 98percent).MS (ES-API, pos. ion) m/z: 246.9 [M + 2]tN-bromosuccinimide (2.12 g, 12.0 mmol)Add to 5-nitrosalicylaldehyde (2.0 g, 11.9 mmol)In a solution of acetonitrile (60 mL), The reaction system was stirred at room temperature overnight.Then add ethyl acetate, Organic phase in turn, Saturated saline solution, Water washing, The organic phase was separated and dried over anhydrous sodium sulfate.filter, concentrate, Methanol was then added to the residue and heated to reflux.Then, water was added dropwise to the reaction system to precipitate a solid, and the mixture was cooled to 0 ° C and stirred for half an hour.filter, The filter cake was dried in vacuo to give compound 26.1 (2.4 g, yield: 82percent) as a yellow solid.General procedure: NH2-Hydroxy-5-nitro-benzaldehyde (2.0 g, 12 mmol) and dichloromethane (30 mL) were added to a 100 mL two-neck flask, then bromine (2.24 g, 14 mmol) was added dropwise. The mixture was stirred for 1 h at rt. The mixture was quenched with saturated aqueous sodium thiosulfate (100 mL), and the resulting mixture was partitioned. The aqueous phase was extracted with ethyl acetate (100 mL x 2). The combined organic phases were washed with saturated brine (80 mL x 2), dried over anhydrous sodium sulfate, filtered, and concentrated in vacuo, the residue was purified by silica gel chromatography (ethyl acetate/petroleum ether (v/v) = 1/20) to give the title compound as a yellow solid (2.89 g, 98%).MS (ES-API, pos. ion) m/z: 246.9 [M + 2]tN-bromosuccinimide (2.12 g, 12.0 mmol)Add to 5-nitrosalicylaldehyde (2.0 g, 11.9 mmol)In a solution of acetonitrile (60 mL), The reaction system was stirred at room temperature overnight.Then add ethyl acetate, Organic phase in turn, Saturated saline solution, Water washing, The organic phase was separated and dried over anhydrous sodium sulfate.filter, concentrate, Methanol was then added to the residue and heated to reflux.Then, water was added dropwise to the reaction system to precipitate a solid, and the mixture was cooled to 0 C and stirred for half an hour.filter, The filter cake was dried in vacuo to give compound 26.1 (2.4 g, yield: 82%) as a yellow solid.General procedure: NH4VO3 (5 mol%) and H2O2 (200 mol%) were placed in a flask. After complete dissolution of the catalyst, TBAB (3 mmol) was added and the mixture was stirred at room temperature. Then, Et2O (10 ml) and aromatic substrate (1 mmol) were added to the mixture. Finally, by slow drip, 1 ml of 1N HClO4 solution was added. After adding the acid, the colour of the reaction changed from yellow to red due to the formation of oxomonoperoxovanadium. Conversion was followed by TLC and determined by GC. The phases were separated and the aqueous phase was extracted with CH2Cl2 (15 ml x3). The organic phases were pooled, washed with brine, dried over Na2SO4 and filtered. The solvent was removed under reduced pressure and the resulting crude product was purified by column chromatography with Hex:AcOEt.The colour formers of the formulae (12) to (17) listed in Table 1 are obtained by carrying out the procedure of Direction 1 and replacing the 3-diethylaminosalicylaldehyde by equimolar amounts of each of the following aldehydes: 5-nitro-salicylaldehyde 5-methoxysalicylaldehyde salicylaldehyde 2-hydroxynaphthaldehyde

Molecular Weight:246.01
XLogP3:2.9
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:4
Rotatable Bond Count:1
Exact Mass:244.93237
Monoisotopic Mass:244.93237
Topological Polar Surface Area:83.1
Heavy Atom Count:13
Complexity:217
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes