136 Report of Schimmel § Co. April 1913. 



The preparation of pinene hydriodide by Wagner and Brickners's method 1 ) is 

 troublesome, and yields poor results, especially in cases where the hydriodic acid 

 cannot be dried completely. According to O. Aschan 2 ), pinene hydriodide can be 

 prepared much more easily by allowing anhydrous magnesium iodide to react upon 

 pinene hydrochloride. On 10 parts powdered magnesium Aschan pours 150 parts 

 absolute ether, the mixture being diluted under steady cooling with 100 parts iodine. 

 When the reaction is completed 136 parts pure pinene hydrochloride are introduced, 

 the mixture being heated for two hours in a reflux condenser. The ether is then 

 distilled off and the residue heated for three hours more in a water-bath. Small 

 pieces of ice are added to the solid residue, the resulting oil is decolorised with bisulphite 

 and driven over with steam. A colourless oil then distils over, wich is heated in a 

 water bath with 400 parts 15 p. c. alcoholic potash liquor and subjected to steam- 

 distillation. In this manipulation a light oil, consisting of camphane and a little bornylene, 

 distils over first, and afterwards a heavy oil which sinks to the bottom and of which 

 the major portion boils between 99 and 100° (6 mm.) (d^ 1,4553). The latter substance 

 is pinene hydrochloride. Pinene hydriodide from faintly rotating or inactive pinene 

 hydrochloride melts at about — 12°; pinene hydriodide from strongly rotating crude 

 material at — 3 to — 5°. 



When treated with freshly-precipitated silver oxide in alcoholic solution, pinene 

 hydriodide yields what is apparently a new terpene alcohol, Ci Hi 7 OH, which is 

 unsaturated, as is evident from its behaviour towards permanganate and bromine. 

 B. p. 207 to 211°. 



The preparation of camphane from pinene hydriodide, which was formerly carried 

 out by Aschan with glacial acetic-hydriodic acid can just as readily be accomplished 

 with hydrogen chloride-glacial acetic acid. In this case the iodide is diluted in the 

 presence of zinc-wool, under steady cooling, with 12 p. c. hydrogen chloride-glacial 

 acetic acid, the mixture being finally boiled for a few hours in a reflux condenser, 

 j. Hamalainen 3 ) has recently succeeded in converting the camphane into camphor 

 derivatives, a fact which is of importance because it proves beyond doubt that camphane 

 forms the basic hydrocarbon of the camphor-compounds. 



On the reduction of pinene, see p. 134. 



Menthadiene. In our Report of April 1912 (p. 173), we mentioned that 

 G. G. Henderson and R. Boyd had obtained a menthadiene from thymol, from primarily- 

 produced thymomenthol and zf 3 -menthene. Henderson, in collaboration with S. P. Schotz 4 ), 

 has now prepared a menthadiene frorn. carvacrol by the same method. He hydrogenated 

 carvacrol in the presence of finely-divided nickel to carvomenthol and converted the 

 latter into a menthene (most probably z^-menthene), by heating with anhydrous oxalic 

 acid. The dibromide of the menthene (1,2-dibromomenthane) when heated with anhydrous 

 sodium acetate in glacial acetic acid solution, or when boiled with alcoholic potash 

 liquor, yielded a menthadiene, b. p. 172 to 174°: d 2 ^ 0,8272, n D 1,46430. So far it is 

 impossible to give definite data with regard to the constitution of this menthadiene, 

 but it is certain that the menthadiene of Henderson and Schotz differs from that which 

 has been prepared from carvomenthyl chloride by Kondakow and Schindelmeiser 5 ). The 

 former affords no nitrite, whereas Kondakow's menthadiene yields a "nitrosite", and is 



x ) Berl. Berichte 32 (1899), 2311. — 2 ) Ibidem 45 (1912), 2395. — 3 ) Comp. Report October 1912, 137. 

 *) Journ. chem. Soc. 101 (1912), 2563. — 6 ) Journ. f. prakt. Chem. II. 72 (1905), 193; 75 (1907), 141. 



