COPPER INHIBITORS FOR POLYOLEFINS

1481388 1,2 - Dinophthoyl hydrazines and their application as stabilizers for polyolefins AMERICAN CYANAMID CO 17 Sept 1975 [18 Oct 1974] 38284/75 Heading C2C [Also in Division C3] The invention comprises compounds of Formula I wherein R is C 1-8 alkyl and X is hydrogen or O-C 1-8 alkyl, the compound being optionally substituted on one or both naphthyl rings with one or more substituents selected from halogen atoms and C 1-4 alkyl groups which may be prepared by reacting 3-alkoxy-2-naphthoyl chloride with the appropriate naphthoylhydrazine of Formula VI where X is H or C 1-8 alkoxy. Methyl 3 - hydroxy - 2 - naphthoate is prepared by reacting 3-hydroxy-2-naphthoic acid with methanol in the presence of sulphuric acid, and subsequently reacted with dimethyl sulphate to obtain methyl-3-methoxynaphthoate from which 2-methoxy-3-naphthoic acid is obtained by treatment with caustic potash and converted to 3-methoxy-2-naphthoyl chloride by reaction with thionylchloride. 2 . Naphthoyl hydrazine and 3 - methoxy- 2-naphthoyl hydrazine are prepared by reacting ethyl 2-naphthoate and methyl 3-methoxy-2- naphthoate respectively with anhydrous hydrazine. The products of Formula IX have applications as polymer additives for the inhibition of copper catalysed thermal degradation of polyolefins.