The stoichiornetries for the oxidation of some substit~rted phenols with cumyl perosy radicals a t 65 "C have been measured. The results can be correlated generally with the expected phenolic oxidation products. Phenols with one or two ~rnsubstituted ortho positions can react with more than 2 peroxy radicals per molecule. A rnaxi~num stoichiornetry of 2.6 perosy radicals was obtained with 2,4-dirnethylphenol. 2,4,6-Tri-substit~~ted phenols generally have stoichiometric factors of 2.0 or less.

The principal products formed from 1-ethoxyethyl hydroperoxide and 1,2-diphenylethyl hydroperoxide on oxidation with reagents that are presumed to generate the corresponding sec-alkylperoxy radicals (Ce(IV), tert-butoxy, and Ag2O) have been identified. The products formed when the corresponding alkoxy radicals are generated in pairs have also been identified. It is concluded that the Russell (1) concerted cyclic mechanism in which tetroxide decomposed to molecular products is not the exclusive route for the bimolecular self-reaction of sec-alkylperoxy radicals. It is suggested that there is also a second tetroxide decomposition process which yields radical products. The second process may yield "free" alkoxy radicals or it may, perhaps, yield the products of β-scission of the alkoxy radicals in a step concerted with O—O homolysis of the tetroxide. The relative importance of tetroxide decomposition to molecular and to radical products will depend on the structure of the alkyl groups, the temperature and, perhaps, the solvent.

Ten p r o d~~c t s f r o m the osidatior~ of 2,4-di-t-butylpher~ol wit11 L-butyl perosy radicals have been identilied. They can be subdivided into three groups, depending on the type of radicalradical coupling reaction by which they are prod~rced or iri which their precursors are forn~ed:(i) pher~oxy-perosy coupling, ( i i ) phenoxjr-phenoxy coupling a t the 6 positior~s, and (iii) phenoxy-phenoxy couplir~g through the oxygen atoll1 of one radical and the 6 positio!~ of the second radical. Products resulting from still other phenosy-phenoxy coupling reactions are undoubtedly formed in 111i11or amounts.The products from the oxidation of 2,4-di-t-butylphenol xrith t-butyl peroxy radicals have been studied as a part of our general investigation into the oxidation of phenols (I). This compound was chosen as a representative 2,1-dialliyl phenol which might be expected to give a simpler mixture of products than a phenol containing a inethyl group, since products coupled through the methyl group (such as dihydroxy bibenzyls and stilbenequinones) would not be formed. In spite of this siinplification 110 less than 10 products were identified, and the thin-layer chromatographic (t.1.c.) plates showed t h a t many others were present. T h e products were separated by coluilln chroillatography on silica ( I ) . Their relative yields depended not only on the exact conditions of the reaction but also on the speed 11-ith nrhich they were separated. The latter variation is due to the fact that inany of the initial products are unstable peroxides which decoinpose on exposure to light and heat and even t o the inildly acidic silica column itself.By analogy with 2,G-dialliyl phenols (I) we inay expect to get products resulting from phenoxy-peroxy and phenoxy-phenoxy radical coupling reactions. Elowever, in the present case, the existence of a hydrogen atom in the 6 positioil leads to products of increased complex it^^ because of the rapid rearrangement of those intermediates \\ ith an o-quinolide structure. For convenience, the overall reaction is divided into three parts.Firstly, combination of the initially forined phenoxy radical with a t-but11 peroxy radical.3,s-Di-t-butyl-o-benzoquinone (11) was one of the major products (-10yo), but its probable precursor (I) \vas not identified. The conversion of I into I1 inay occur either directly (cf. ref. 1) or after rearrangement to an o-peroxy phenol. The 4-peroxy-cyclohexadienone, 111, found in s-lOyO yield, is siinilar to the major products formed fro111 ,3,4,6-trialliyl phenols (1). Co~npound I11 decolnposed slo~vly on the t.1.c. plates to give 2-t-butyl-p-benzoquinone (I\[) and other unidentified products. No compound corresponding t o the addition of the peroxy radical a t the 2 position of the original phenol \\-as identified, nor was its expected decomposition product, 4-t-but)il-o-benzoquinone, detected.Secondly, colllbination of two phenoxy radicals through their carbon atoms in position 6. T h e biphenol V and its precursor mere not identified anlong the products under the s...

The di-(1-adamantyl)iminoxy radical, (1-Ad)2C=NO•, has been prepared from the corresponding imine. It is a blue, crystalline material that is stable indefinitely in air at room temperature in the solid state. Dipole moments have been measured in benzene at 30° for the radical (2.90 D), for (1-Ad)2C=NH (2.49 D), and for (1-Ad)2C=NOMe (0.79 D). In the radical the unpaired spin density on nitrogen is estimated to be ca. 25%.

Previous work on the oxidation of alkyl phenols with peroxy radicals is summarized. The yields of the peroxy-cyclohexadienones formed from 2,6-di-t-butyl-4-methylphenol in the α,α′-azo-bis-isobutyronitrile-initiated oxidation of tetralin at 40 °C have been measured quantitatively. The results suggest that not all the oxidation chains are initiated by isobutyronitrile peroxy radicals.The products from the oxidation of 2,6-di-t-butylphenol and 2,6-dimethyiphenol with (butyl peroxy radicals are found to be mainly dialkyl-p-benzoquinones and tetraalkyl diphenoquinones.