Diphenylamine-2-carbonyls

N[CeHa(N02)2].CO mw 570.42, N 14.73% ndls (from acet + alc), mp — dec readily sol in acet, chlf, ben2, acet ac, S phenol si sol in ale, eth, CSg CCI4 was prepd from reaction of 2, 4 -dinitro-diphenylamine-2-carbonyl chloride pyridine (Refs 2 3)... 

Carbonyl chloride in air at maximum allowable concentration may be measured by colorimetry. Prepare a solution containing 5% p-dimethylaminoben-zaldehyde and 5% diphenylamine in carbon tetrachloride. Soak a paper in this solution. Allow it to dry. The color of the paper turns from yellow to deep orange in the presence of carbonyl chloride. 

In connection with a study of a number of anticancer compounds which, presumably also act as inhibitors of free-radical polymerization, eight classes of compounds were studied as to their inhibitory properties. The classes studied were unsaturated hydrocarbons, phenolic compounds, quinones, amines, stable free-radicals, sulfiir compounds, carbonyl compounds, and metallic salts. The most effective inhibitors, of those evaluated, were cupric acetate and cupric resinate, followed by /runs-1,3,5-hexatriene, hydroquinone, benzoquinone, and diphenylamine as modest inhibitors. Among the low-activity inhibitors were 2,2-diphenyl-1-picrylhydrazyl, benzene thiol, and crotonaldehyde [70]. 

On the other hand, mechanisms differing from the above in the order of dehydration have been proposed by Hurd and Isenhour, by Isbell (68), and by Wolfrom, Schuetz, and Cavalieri (69). The mechanism of the latter involves in the first two dehydrations the production of adouble bonds in a manner generally characteristic of jS-hydroxy carbonyl compounds. To be noted also is the apparent greater ease of dehydration (indicated by the Dische diphenylamine test, presumably a measure of the hydroxylevulinic aldehyde formed) of arabinal and xylal as compared to 2-deoxyribose (70), although the former are known to have pyranose rings. 

The higher nucleophilicity of amines allows them to win the competition, as only amides are usually formed in carbonylation in the presence of amides and hydroxide ions or small amounts of water. However, for less-reactive arylamines, water puts up a stronger competition. Thus, in the carbonylation of p-nitroiodobenzene in the presence of p-iodoaniline, which gives only p-O2NQH4CONHC6H4I-P in DMF, the addition of only 5vol% H2O results not only in sharp acceleration of reaction, but also in the formation of considerable amounts of nitrobenzoic acid. No amide was formed in the carbonylation with such a weak nucleophile as diphenylamine [116]. 

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