Question

Ddt preparation mechanism

Answer 1

Answer:

To a three-neck round-bottom flask fitted with a mechanical stirrer and a thermometer 350 g of 95 % sulfuric acid, 50 g of oleum (20 % of free sulfur trioxide), 45 g monochlorobenzene, and 34 g chloral hy­drate were added. The mixture is stirred rapidly and at the end of an hour the DDT separates as a fine granular solid. During the reaction the temperature rises to 45°C. For the completion of the reaction the stirring is continued for an additional half hour. The reaction mixture is poured with stirring into two liters of a 1:1 mixture of ice and water and the solid product which separates is collected on a funnel with suction and washed with cold water. To remove an excess of inorganic acid, the crude DDT is transferred to a beaker containing 500 ml. of boiling water. The mixture is stirred well and allowed to cool, whereupon the washed reaction product solidifies. This process is repeated few times and finally order to completely remove the last traces of acid a little sodium bicarbonate is added to the last wash water. The crystals of DDT is filtered and dried yielding 50 g of crude DDT, which corresponds to over 70 % of the theoretical with melting point 90°C. DDT could be purified by crystallizing from ethyl or propyl alcohol yield product with melting point 108°C. The pure product separates as fine colorless needles that have a slight odor of fresh apples.