Anthracene purification using dimethyl-acetamide as solvent - for removal of impurities and recrystallisation of anthracene

摘要

Sepn. of anthracene (I) from crude (I) involves treatment with an aprotic bipolar solvent (II), giving a suspension, sepn. into a liquid and a solid phase (III) and treatment of (III) with (II). The (II) used is N,N-dimethylacetamide (DMA) and (III) is treated with DMA at 52-135 degrees C., giving a second suspension contg. insol. impurities. These are sepd. and the remaining soln. is cooled to -10 to +40 degrees C., giving a suspension contg. (I) crystals, which are sepd. (I) is widely used, e.g. for the prodn. of anthraquinone, alizarin and indanthrene dyestuffs, monomers for the prodn. of high-mol. prods. with complex valuable properties, special lubricants and scintillators. The degree of sepn. of (I) is increased, and (I) is obtd. in a pure purer form than by treatment with acetone.