Notes on scientific research. 151 



quantity of 2N-alkali made up free from carbonate, and evaporating to dryness in a 

 vacuum desiccator. The salts were coloured red or blue, corresponding either to the 

 nitroso or to the isonitroso (oximido) type. The silver salt of nitrosocarvacrol was 

 at first greenish-brown, turning later to olive and finally brown. 



For identifying both phenols, the benzoyl derivatives of the nitroso compounds are 

 particularly useful: — benzoyl nitrosothymol, (from alcohol, m. p. 109 to 110.5°; no oxime 

 obtainable); benzoyl nitrosocarvacrol (from alcohol, m. p. 85 to 87°; oxime, obtained by 

 treatment with hydroxylamine hydrochloride and sodium bicarbonate; m. p. from benzene, 

 156 to 157° with evolution of gas). Alkali transforms the oxime into nitrosothymol. 



By treating the alkali salts of both nitrosophenols with methyl iodide in alcoholic 

 solution, the author obtained nitrosocarvacrol methyl ether (m. p. 39°) and nitrosothymol 

 methyl ether (liquid). 



Isosafrole. — S. Nagai 1 ) reports on the various geometrical isomerides of isosafrole, 

 on which Hoering and Baum 2 ) had published a paper some time ago. When safrole 

 is rearranged to isosafrole, the stable trans-form is obtained best by heating 1 pt. safrole, 

 0.5 pt. potassium hydroxide, and 1 pt. 98 per cent, alcohol up to 94 to 95° for four to 

 five hours. The labile cis-form, which on heating passes over into the other isomeride, 

 is formed when using less alkali and more alcohol and at a lower temperature. The 

 author describes the following preparations: — c (cis)-isosa.fro\e (b. p. 242 to 243°; 

 df^ 1.1 162 to 1.1168; n D150 1.5630 to 1.5632; picrate, m. p. 68.5°); t (trans)-isosafro\e 

 (b p.247to 248°; d^l.l230to 1.1235; n D15Q 1 .5730 to 1.5736; picrate, m. p. 73.5 to 74°). 

 The dibromides of both isomerides differ merely by the angle of rotation: — cis-dibromide, 

 Mdmo + 13.35°, frans-dibromide, [«] D20 o + 4.45°. 



By distilling in vacuo or by heating with potassium hydroxide, the £-dibromide 

 yielded the c-monobromide (b. p. 168 [19 mm.]), and vice versa, the c-dibromide gave 

 the f-monobromide (b. p. 154° [19 mm.]j of isosafrole. cis-Isosafrole monobromide as well 

 as f-dibromide, when heated to 70°, readily split off hydrogen bromide with formation 

 of piperonyl allylene CH 2 2 :C 6 H 3 -G \ CCH 3 (m. p. 41 to 42°, b. p. 249 to 251°). On 

 the other hand, f-monobromide and c-dibromide yielded piperonyl allylene only when 

 heated to 150° and with an excess of alkali. 



On heating the monobromides with zinc and alcohol, the author obtained the 

 corresponding isosafroles. This reaction furnishes a method of obtaining, from c-iso- 

 safrole, via the bromine compounds, fnms-derivatives, and again leads back to the 

 initial body. 



By oxidising both isomerides with potassium permanganate or ozone, the same 

 body, piperonal, resulted. 



A new method for the preparation of the alkamines of anethole, isosafrole, and 

 methyh'soeugenol has been published by J. Takeda and S. Kuroda 2 ). The pseudo-ureas 

 of these bodies, obtained from their dibromides with urea, are constituted, in the 

 opinion of the authors, as demonstrated by the annexed formula, and on treatment 



with acetic anhydride and sodium acetate they yield the acetyl R-CH NH 



derivatives and the acetylated oxazolidones. These bodies are | \C : NH 



broken up, on boiling with alkali, more readily than the v^-ureas R *CH O' 

 and lend themselves, therefore, preferably for the preparation of the alkamines. Following 

 this method, the authors arrived at the following derivatives: — anethole alkamine 



l ) Joum. Coll. Engin., Tokyo 11 (1921), 83. From a special reprint kindly forwarded to us. — 2 ) Joum. 

 pharm. Soe. of Japan 1921, No. 467. As per Chem. Zentralbl. 1921, I. 789. 



