Notes

Abstract

By R. F. MOORE and WILLIAM A. WATERS.A KINETIC study (Part I11 *) indicated that when 3 : 5 : 3' : 5'-tetramethyl-4 : 4'-diphenoquinone is used as a retarder of the benzoyl peroxide-catalysed autoxidation of benzaldehyde it acts by combining with the free benzoyl radical, C,H,*CO*, probably to form 4 : 4'-dibenzoyloxy-3 : 5 : 3' : 5'-tetramethyldiphenyl. However, the true location of the added benzoyl group cannot be deduced by kinetic methods and the direct isolation of the chain-ending product was therefore undertaken. The dibenzoate has in fact been isolated but, as pure product, in the yield of 5% only. There was also produced a considerable quantity of a yellowish amorphous powder of indefinite m. p. (140-190") which could not be purified. I t would seem therefore that the kinetic analysis of this retarded autoxidation leads to a representation which very much simplifies the organic chemistry of the whole processes, and it may be recalled that a similar impression of the validity of kinetic study alone has previously been reached from studies of the retardation of benzaldehyde autoxidation by phenols (compare Parts I and 11,

Quinone studies. Part III. Metal ion-catalysed oxidation of halophenols and halonaphthols by peroxidisulphate

“…Ortho-blocked phenols like 2, 6-dimethyl phenol have been reacted with chromic acid (Horswill and Ingold 1966), hydrogen peroxide-copper(II) salt (Walling and Hodgdon 1958), t-butyl hydro-peroxide (Moore and Waters 1952), alkaline ferricyanide (Haynes et al 1956) and peroxysulphate-silver (I) salt (Bacon and Munro 1960) to give the corresponding diphenoquinone.…”