METHOD OF PREPARING POLYMERIZATION INHIBITOR OF UNSATURATED HYDROCARBONS Russian patent published in 1998 - IPC

FIELD: chemical industry. SUBSTANCE: present invention describes method of preparing polymerization inhibitor of unsaturated hydrocarbons based on 2,2′,6,6′-tetramethyl-4-oxopiperidin-1- oxyl. The claimed method comprises oxidation of 2,2′,6,6′- tetramethyl-4-oxopiperidine with hydrogen peroxide in the presence of carbon dioxide in amount of 0.03-2 wt % as catalyst. Stock includes hydrocarbon fraction which contains at least 85 wt % 2,2′,6,6′-tetramethyl-6- oxopiperidine. Oxidation is accompanied by presence of water or organic solvent and also trilone B. The desired product is recovered by extraction with organic extracting agent and is subsequently distilled. 5 to 95 wt % extracting agent is distilled. The claimed method makes it possible to simplify preparation of polymerization inhibitor increase its yield and improve efficiency. EFFECT: more efficient preparation method. 5 tbl, 7 tbl