CXCII1.-The Bromination of Pheizol. 2 : 4-and 2 ; 6-Dibrornophenok By FRANK GEORGE POPE and ARTHUR SAMUEL WOOD. CONSIDERABLE quantities of 2 : 4-and 2 : 6-dibromophenol being required for an investigation now in progress, it was found that the preparation of these compounds was, as a rule, attended by considerable difficulty, and that the yields obtained were in most cams rather small, more especially in the case of 2:6-dibromophenol. Korner (A n d e n , 1866, 157, 205) prepared 2 : 4-dibromophenol by the direct bromination of phenol in the cold, whilst Peratoner

By JOCELYN FIELD TRORPE and ARTHUR SAMUEL WOOD.THE experiments described in the previous parts of this series have shown that a derivative of glutaconic acid containing the mobile hydrogen atom should, theoretically, exist in three forms, namely :

The quaternary salts are formed a t the ordinary temperature, and the rate of formation is dependent on the nature of the halogen derivative used ; their formation is, moreover, facilitated by the addition of a trace of some hydroxylic solvent, such as alcohol.

No abstract

DURING the course of the experiments described in Part XV of this series (T., 1911, 99, 422), which dealt with the products formed by the condensation of ketones with cyanoacetamide in the presence of piperidine, it was shown that whereas the chief product is the cyclic imino-compound I, a second substance is always formed in small amount, which can be distinguished from the imino-compound by being soluble in dilute alkali. Considerable quantities of this by-product having accumulated, we have been enabled to establish its structure, although considerable difficulty was experienced in obtaining concordant results on analysis.Ultimately this trouble w u overcome by mixing the substance in the boat with powdered lead chromate and using the modified form of the nennstedt furnace which is in vogue in the laboratories a t Manchester. There can be no question that the by-products which are produced from acetone, methyl ethyl ketone, and c y d ohexanone are identical with the compounds obtained as the main products by Guareschi and his collaborators in the interaction of the ketones and ethyl cyanoacetate in the presence of alcoholic ammonia, and which have a structure represented by formula IT: CN*YH--CO CN-YH-CO