The weights of bromosultone obtained from 0.2-g. mixtures of (I) and (II) were as follows: 0% (I), very small amount of oil; 10% (I), small amount of oil; 20% (I), 0.10 g.; 30%, 0.12 g.; 40%, 0.13 g.; 50%, 0.14 g.; 60%, 0.16 g.; 70%, 0.19 g.; 80%, 0.21 g.; 90%, 0.22 g.; 100%, 0.235 g. (95% yield). The oil formed from (II) on treatment with potassium tribromide solution contaminates the bromosultone so that all samples 'from mixtures of the two salts are low melting. A mixture of sodium 2-hydroxy-3-phenyl-2-methylpropane-l-sulfónate with (I) did not alter the quantity or purity of bromosultcme obtained from the latter. No solid bromosultone was obtained on addition of potassium tribromide solution to solutions of (II) (sodium salt) which were allowed to stand at room temperature with or without the addition of alkali (5% NaOH solution) or acid (10% HC1 solution) for periods of from one to seven days. Heating at 100°c aused as much as 70% rearrangement in twenty-four hours in acid or basic solution but no change in neutral solution. No rearrangement was observed after three hours at 100°in acid, basic or neutral solution. . Sodium 2-Hydroxy-3-phenyl-2-methylpropane-l-sulfonate.-3 -Phenyl -2 -methyl -2 -hydroxy -1 -bromopropane was prepared from 13 g. (0.1 mole) of 2-benzyl-lpropene according to the directions of Read and Reid." The crude bromohydrin was added slowly to a saturated solution containing 12 g. (0.1 mole) of sodium sulfite in 10% sodium hydroxide. The mixture was stirred and heated on the steam-bath for forty-eight hours. Working up the reaction mixture gave 9 g. (0.035 mole) of organic sodium salt, which was extremely soluble in water and slightly soluble in alcohol (35% yield of crude salt). Separation from inorganic salts was difficult.The S-benzylthiouronium salt was prepared and crystallized with difficulty from alcohol-water mixtures, m. p.
The Preparation of -BROMO-a,/3-unsaturated Ketones and Esters 1145 [Contribution from the Research Laboratories of the Vick Chemical Company]The Preparation of a-Bromo-,/3-unsaturated Ketones and Esters By Cyril H. Nield Two general methods have been used for the synthesis of -halogen-a,ß-unsaturated ketones.In the first method1 halogen is added to an a,/3-unsaturated ketone and hydrogen halide is then removed with the aid of a basic agent such as sodium alcohólate, alcoholic alkali, alkali acetate, or pyridine. This procedure has been used successfully with the relatively stable unsaturated ketones of the aromatic series such as benzal acetone and anisal acetone.Few completely aliphatic -halogen-a,/3-unsaturated ketones have been described. a-Bromoisobutylidene acetone and a-chloroisobutylidene acetone,2 -bromoethylidene acetone,1 and , 'dibromophorone and , '-dichlorophorone3 have been prepared by the above procedure from mesityl oxide, ethylidene acetone, and phorone, respectively. The same method has been used for the preparation of -halogen-a,/3-unsaturated acids and esters, which are generally obtained in good yields from the corresponding unsaturated acids4 or esters.6
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