METHOD OF SYNTHESIS OF DI-P-XYLYLENE Russian patent published in 1995 - IPC

FIELD: organic chemistry. SUBSTANCE: steam is superheated up to 950-960 C and mixed with p-xylene vapors containing triphenylphosphine at the ratio (97.5-99.5):(2.5-0.5), and mixture is pyrolyzed at 930-940 C in the presence of catalyst followed by passing postpyrolysis zone filled with Raschig rings or regular packing made of quartz glass at the ratio of packing volume to the free zone volume 0.1-1.6. Vapors of p-xylene were fed to the hollow transporting zone at 400-450 C, and pyrolysis gases in p-xylene were absorbed at 80-130 C. The end product is isolated by crystallization, filtration and recrystallization from organic solvent. Synthesized di-p-xylylene contains up to 99.9% basic substance. EFFECT: improved method of synthesis. 12 cl, 3 tbl