The Preparation of Some Substituted Piperazines 263 tained pure because both were very hygroscopic. The picrate and picrolonate were obtained as well-characterized crystalline salts.Picrate.-Prepared in and recrystallized from absolute ethanol, the picrate formed yellow elongated prisms which softened at 210°and melted, with decomposition, at 218.5-219.5°(cor.).

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Nord, el al.,1 condensed acetaldehyde with magnesium aluminum alkoxide catalysts ánd isolated from the reaction product the monoacetate of l, 3-butanediol. No mention is made in their papers of the ethyl ester of /3-hydroxybutyric acid which we have found to be present in the reaction mixture in approximately equimolecular proportion to the monoacetate of 1,3-butanediol. Similar proportions of the diol and the hydroxy acid have also been found in an oily by-product obtained in the commercial preparation of ethyl acetate from acetaldehyde.2Experimental.-The procedure adopted for separating the constituents of the high-boiling oils was as follows:(1) Acid hydrolysis with excess water and butanol: the mixture was heated in a flask provided with a packed distillation column. The overhead temperature was kept at the boiling point of the butyl acetate-butanol-water ternary azeotrope by adjusting the reflux ratio. The estercontaining top layer of the distillate was drawn off while the water layer was decanted back to the flask. This was continued until the temperature could no longer be kept below 90°by refluxing. The excess butanol was then removed in the same manner at a temperature of 92°.(2) Neutralization and saponification: the saponification equivalent of the aqueous residue was determined, and just sufficient sodium hydroxide was added in 10% solution to neutralize the free acid and saponify the remaining esters. The mixture was boiled for an hour and cooled.(3) Filtration to remove any resinous by-products. (4) Vacuum distillation of filtrate: the excess water Notes Vol. 70 under the above conditions but benzoquinone (and perhaps the intermediate quiñones) can be. If the concentration of cupric ion is significantly diminished such oxidations take place and the yield is less. In the presence of 0.01 mole of cupric acetate the oxygen -absorption was about the same but the bisaminoquinone was then obtained in 72-76% yield.