Diacetyl p-phenylenediamine

Diacetyl-o-phenylenediamine AT -Diacetyl-m-phenylenedi amine AT -Diacetyl-p-phenylenediamine... 

Yellow needles from MogCO.Aq. M.p. 180° (188°). Spar. soL cold EtOH, hot HjO. Cone, caustic alkalis —> 2 4-dinitrophenol. (NHg)gS —> 4-nitro-o-phenylenediamine + 2-nitro-p-phenylenediamine. Forms no salts. Acetyl see 2 4-Dinitroacetanilide. Diacetyl m.p. 112-13°. 

Method 4. Polymerization of Diacetyl and / -Phenylenediamine The polycondensation of diacetyl with p-phenylenediamine yields a dark-brown, amorphous powder that is soluble in dimethylformamide, formic acid, and sulf uric acid. Its structure was thought to be a poly(Schiff base). However, ozonization and infrared studies demonstrated that the most probable structure of the polymer was [23] (33). Since diacetyl dimerizes to a product which yields p-xyloquinone in basic medium, the polymer [23] could have arisen from the reaction of p-xyloquinone with the diamine (53). 

Normal nitroso derivatives which cannot be prepared with nitrous fumes from certain compounds can be formed by means of nitrosyl chloride. In particular, the nitroso derivatives of p-nitroacetanilide and of diacetyl-1,3-phenylenediamine can be prepared.- However, 2,4,6-trinitroacetanilide and 2,5-diethoxydiacetyl-l,4-phenylenediamine have resisted nitrosation even by this method. 

Terphenyl.8, 68 To a stirred solution of 10 g. of diacetyl-1,4-phenylenediamine in a mixture of 150 cc. of glacial acetic acid and 75 cc. of acetic anhydride containing 12 g. of anhydrous potassium acetate and 1 g. of phosphorus pentoxide at 8° is added dropwise a solution of 8 g. of nitrosyl chloride in acetic anhydride. The mixture is poured onto ice and water, and the yellow Jw s-nitrosoacetyl-1,4-phenylenediamine is filtered and dried yield, 11.4 g. m.p. 124° dec. 

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