2-Chloro-4'-bromo-5,3'-dinitro benzophenone → Hydrochloric Acid

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Reaction Steps

In a closed glass vessel there are charged 38.6 g (0.1 moles) of 2-chloro-4'-bromo-5,3'-dinitro benzophenone, 1 g of palladium black catalyst and 300 ml of benzene. While the mixture being stirred at 65°-70° C., hydrogen is introduced into the vessel so that 13.8 l (0.62 moles) of hydrogen is absorbed in the mixture during 8 hours. Then, there are added 90 g (0.24 moles) of 15% aqueous solution of NaOH and 2 g of 90% aqueous solution of trioctyl methyl ammonium chloride, and then, there is introduced again hydrogen, while the mixture is being stirred at a temperature of 65°-70° C., so that 4.5 l (0.2 moles) of hydrogen is absorbed during about 5 hours. By filtering the reaction liquid at 65°-70° C. the catalyst is removed, and organic phase is separated from the filtrate. After the organic phase is added with magnesium sulfate for water removal, it is introduced with dry hydrochloric gas until saturated with the gas. The crystals thus formed are filtered, washed with 50 ml of benzene and dried to give 3,3'-diamino benzophenone in the form of hydrochloric acid salt. Yield 21.7 g (76%). Recrystallization from 20% aqueous isopropanol yield slightly yellow needle-like pure crystals of the benzophenone. M.P. 267° C. (decomposed).

Provenance & Evidence