L. CHAS.RAIFORD AND EDWARD L. HILL
174
[CONTRIBUTION FROM THE
LABORATORY OF ORGANIC
Vol. 56
CHEMISTRY OF THE STATE UNIVERSITY O F IOWA]
Effect of Constitution on the Rearrangement of the Phenylhydrazones of Some Unsymmetrically Substituted Dibenzalacetones’ BY L. CHAS.RAIFORD AND EDWARD L. HILL In a recent report from this Laboratory2 there methoxy-, 4-ethoxy-, 4-propoxy- and methylenewas described work on the rearrangement of the 3,l-dioxystyryl ketones reacted with phenylphenylhydrazones of certain unsymmetrically hydrazine likewise failed to respond to tests for substituted3 dibenzalacetones to the isomeric hydrazones, and were probably pyrazolines. pyrazolines. Oxidation of the latter gave 1,s- Oxidation gave, in the first two cases, benzoic and diphenylpyrazole-3-carboxylic acid and benzoic the pyrazole acids required by structure A. In or a substituted benzoic acid, indicating that the the last case, oxidation of several portions always closing of the pyrazoline ring involved the un- gave benzoic acid, which indicated structure A. saturation farthest from the nucleus bearing the When the product obtained from di-(methylene“acid-forming” substituent. The present paper 3,4-dioxystyryl) ketone was oxidized, no acid deals with the behavior of compounds containing could be isolated, which indicated complete “non-acidic” groups, viz.,alkyl, alkoxy1 and alkyl- degradation.6 amino radicals. The action of phenylhydrazine on styryl 4Treatment of styryl 4-methylstyryl ketone dimethylaminostyryl ketone gave a product that with phenylhydrazine gave a product that could was regarded as a hydrazone. While i t could not not be reduced by sodium amalgam, that suffered be reduced by sodium amalgam it was rearranged no change when boiled with acetic acid, and which by boiling acetic acid. It was also hydrolyzed by was regarded as a pyrazoline. Analyses for sulfuric acid and the presence of phenylhydrazine starting material and product (see Tables I and in the reaction mixture was established by oxida11) agree with l-phenyl-3-styryl-5-(4-methyl-tion with Fehling’s solution. Although the phenyl)-pyrazoline, with structure A volume of nitrogen obtained (see experimental part) was little more than one-half that required --s by theory, the fact that none was liberated when the corresponding rearranged product was subC I I B c ) - - C H - - . C H 2 --C- -CH=CHjected to the same treatment clearly indicated A that the first compound was a hydrazone.’ and with 1 -phenyl-3-(l-methylstyryl)-S-phenylExperimental Part pyrazoline, of structure B
(->
/I
Preparation of the Ketones.-To
a solution of 30 g. of
