ISOMERISATION OF BENZYLIDENE DERIVATIVES. PART I

The red dibenzylidene compound obtained by condensing benzaldehyde with 4 :6- dianilino-1 :3-diaminobenzene, when boiled with alcohol, isomerises to a yellowish white substance, which is not hydrolysed by the action of dilute acids. Similarly the benzylidene compounds, prepared by condensing other aromatic aldehydes with the above diainine and with 4 :6-\(o\)-toluidino-1 :3-diaminobenzene, undergo isomerisation, whereas the dibenzylidene derivative of 4 6-Inesidino-1:2-diaminobenzene remains unchanged. The results are interpreted on the basis of the formation of derivatives of dihydroftuorindene.