5-Chloro-2-nitrobenzaldehyde

51282-49-6

6628-86-0

The general procedure for the synthesis of 2-nitro-5-chlorobenzaldehyde from methyl 2-nitro-5-chlorobenzoate was as follows: to a stirred mixture of methyl 2-nitro-5-chlorobenzoate (8.20 g, 38.0 mmol) and anhydrous dichloromethane (205 mL) at -78 °C, diisobutylaluminum hydroxide (DIBAL-H, 48.0 mL. 48.0 mmol, 1.0 M in dichloromethane). After 45 minutes of reaction, methanol (20 mL) was added and the reaction mixture was gradually warmed to room temperature. Subsequently, 10% aqueous sodium tartrate (200 mL) was added and the suspension was vigorously stirred until the two phases separated. The reaction mixture was diluted with dichloromethane (100 mL) and washed sequentially with water (2 x 100 mL), saturated aqueous sodium bicarbonate solution and saturated aqueous sodium chloride solution (2 x 100 mL). The organic phase was dried with anhydrous sodium sulfate and purified by silica gel fast column chromatography with 20-50% ethyl acetate/hexane as eluent to afford the target product 2-nitro-5-chlorobenzaldehyde (6.80 g, 36.7 mmol, 97% yield). The structure of the product was confirmed by 1H NMR (400 MHz, CDCl3) and 13C NMR (100 MHz, CDCl3).