Preparation of 2-nitrobenzaldehyde
In round boiling flask containing 500 ml 100 ml toluene is placed ax ml of nitric acid (60%). The flask fit the return water condenser and heat the reaction mixture to water at 30 ° C. After 8 hours heating is interrupted, and the flask add 200 mL of water.
Two-liter boiling flask fitted with a magnetic stirrer and a thermometer placed in an ice bath. In the flask, 600 g (570 ml), glacial acetic acid, 612 g (565 ml, 6 mol) of acetic anhydride and 50 g (0.36 mol) of 2-nitrotoluene. To this mixture slowly and under stirring are added 156 g (85 mL, 1.5 mol) of conc. sulfuric acid. After cooling the mixture to 5 ° C begin to add 100 g (1 mol) of chromium trioxide at such a rate that the temperature did not exceed 10 ° C (takes about 2 hours). After the addition of chromium trioxide stir for 5 hours. The reaction mixture was poured into 6-liter container into thirds filled with crushed ice and add the 6 liters (best mix is divided into three jars). Matter 15 minutes intensively mix that we supported solidified oily layer. Tough oily layer filters out the Buchner funnel and pardons cold water. Stir the precipitate with 500 ml of 2% sodium carbonate solution, filtered and washed with cold water and again filtered. Dissolve the crude product at 60-70 ° C in 150 ml of petroleum ether (dissolution takes about 30 minutes), cooled down and filtered.