No abstract

12 13 selves. The action of acids upon aryl-oxyxanthenols has been the shbject of numerous investigations.' It has been generally reported that they gave rise to colored "oxonium" salts of the constitution (111). We have made a systematic study of this reaction with respect to the oxyxanthenols as an introduction to the study of the constitution of fluoran, fluorescein, hydrochinonphthalein, etc. Our results, as far as they have gone, differ materially from those reported in the literature. We find: (I) that methoxy-and kydroxyxanthenols, except as specified below under (3), yield colorless carbinol chlorides, just like the other xanthenols studied; (2) that these carbinol chlorides tautomerize with extreme readiness to the quinocarbonium salts in the presence of excess of acid, forming acid chlorides; (3) that when one of the two phenyl nuclei in the xanthone ring contains a hydroxy group in the para position to the carbinol carbon atom, then the normal carbinol halides, even in the absence of excess of acid, tautomerize spontaneously to the colored quinoid state, similarly to the benzo-7-pyronoles.' In this preliminary' paper we shall merely give the results as regards the composition of these colored salts. The method of preparation, the properties of the colorless carbinol halides, their various reactions, the double salts, etc., will be given in a later paper. Total chlorine.