CCXXXVI.—Studies in phototropy and thermotropy. Part II. Naphthylideneamines

Alfred Senier, Rosalind Clarke
1911 Journal of the Chemical Society Transactions  
IN previous communications on certain Schiff's bases (Senier and Shepheard, Tram., 1909, 95,441, 1943) several of these compounds were d d b e d , some of which possessed phototropic properties, and nearly all of which were thermotropic. It was noticed that those exhibiting phototropy were all derived from salicylaldehyde, in which the substituents are in the ortheposition with respect to each other. Moreover, other investigators have shown generdly that when isomerism occurs among Schiff's
more » ... among Schiff's bases the compounds are orthoicompounds, with a few exceptions, when they are par*. This being 80, it seemed interesting to continue the search for phototropy and thermotropy among compounds cf this c l w , and, for this purpose, we have preparsd and studied a number of new bases derived from 2-hydroxy-a-naphthaldehyde, in which the naphthalene nucleus takes the place of the benzene ring in salicylaldehyde. None of the bases described proved to be phototropic, but all show thermotropy in greater or less degree. A t the "lower tempem ture " (Zuc. cit.) all becorns paler in colour, and at the " higher temperature " deeper; orange becomes yellow, and yellow, orange, or, in the case of the aminophenol derivatives, red. The bases, uaphthylidenearnines, were prepared by bringing together molecular proportions of the aldehyde and mine in alcoholic solution, and recrystallking the crystals thus obtained from that medium or from methyl alcohol. 2-Hydroxp-a-naph t?iyl~~ene-~c?, crystalliw from alcohol in yellow needles, which are sparingly soluble in ether, but readily so in acetone, chloroform, or light petroleum. It melts at 144-5O (corr.) : 0.4860 gave 21.0 C.C. N2 (moist) at 15O aad 733 mm. N=4.88. Cl7Hl2ONC1 requires N = 4.97 per cent. 2-Hydro xg-a+zaph t ?i yliden e-ni-ch~lor oaniline, OH*C1"H,* CH :N-C6H,C1, occurs in orangeyellow needles when crystallised from alcohol or light petroleum. It is sparingly soluble in ether, readily 80 in benzene, chloroform, or acetone, and melts at 116-117° (corr.) : 0.5222 gave 23.7 C.C. N2 (moi.t) at 16*5O and 748 mm. N=5*20. C,7H,20NCl requiree N=4*97 per cent. 6 u 2
doi:10.1039/ct9119902081 fatcat:i4ofwriyavctvncrhirbn7qafq