﻿18 CLOVER. 



the product formed by the action of sulphuric acid upon American tur- 

 pentine oil. This body, as given above, is substantially the substance 

 described by Wallach, who also obtained it from the oils resulting 

 from the action of sulphuric acid upon terpine hydrate, terpineol and 

 cineol. Wallach gives 185° to 190° as the boiling point of the fraction 

 yielding the bromide in the first case noted. Baeyer 14 also studied the 

 substance and found that the bromide was best prepared from the oil 

 which resulted from the action of a boiling solution of oxalic acid upon 

 terpineol. By reducing the tetrabromide with zinc dust in cold acetic 

 acid, Baeyer obtained a product which boiled from 183° to 185° and which 

 gave a good yield of the tetrabromide. He found the terpinolene to be 

 rapidly changed by the action of heat. 



The oil from this sample as described above was, as usual, shaken out 

 with a dilute solution of caustic potash, then dried over solid caustic 

 potash. It was redistilled on the next day and at 37 millimeters its 

 boiling point was practically constant, at 80° to 81°. The physical 



constants of the oil were now as follows: sp. gr. , 3 4 °= 0. 8360; a ^= -f 1°. 7; 



n 30=1.4701; boiling point; 173°. 5 to 175°. 



Up to this time only one day had elapsed since the removal of the oil 

 from the resin. The alteration in its rotation between the second and 

 third distillations was thought to be unusual and with the idea of accel- 

 erating any change which was possibly' taking place in the oil, a portion 

 of it was heated for 3 hours in a tightly stoppered distilling bulb, im- 

 mersed in an oil bath at 200°. The product was then distilled over and 

 the range in boiling point appeared to be greater than before heating. 

 The amount of polymerization was very small. The distillate showed 

 a rotation of — 7°. 5, and was found to give "a precipitate of phellandrene 

 nitrite, although the amount obtained was not large. After the usual 

 treatment of the crude product, namely, dissolving it in chloroform and 

 precipitating with ether, it was recrystallized from acetic ester without 

 warming and found to melt at 119° to 120°. The quantity was small, 

 but a reading made in an approximately 1 per cent acetic ester solution 

 showed it to be decidedly lawo-rotatory. 



Pour or five days later an attempt was made to prepare more of the 

 terpinolene tetrabromide from the purified oil. The tetrabromide ob- 

 tained in acetic acid was recrystallized from acetic ester and now melted 

 at about 120°. It appeared more like dipentene tetrabromide that it did 

 like the derivative of terpinolene and on recrystallization melted at 125°. 

 The expirement was carefully repeated twice; the bromide, dissolved 

 in an equal volume of glacial acetic acid and well cooled was carefully 

 added to an equally well cooled solution of the oil in 1.5 volumes of glacial 

 acetic acid. The crude bromide, when recrystallized from acetic ester, 



u Ber. d. chem. Gcs. (1894), 27, 447. 



