102 



Report of Schimmel $ Co. 1921. 





The fairly-rapid formation of an additive compound between bromine and tricyclene 

 led to a liquid dibromide 1 ), possibly according to the following scheme: — 



H 2 C 



C(CH 3 ) 2 



C-CHs 



Br 



HX 



BrHC 



C(CH 3 ) 2 



CH 



Tricyclene dibromide (?) 

 (constitution not yet certain). 



A complete elucidation of the above-mentioned transformation was obtained by 

 the treatment of tricyclene and of camphene with gaseous hydrochloric acid. Both 

 these compounds yielded then, the true, so far unknown, camphene hydrochloride 

 (m. p. 125 to 127°), the chloride of Aschan's camphene hydrate 2 ). The camphene 

 hydrochloride is, as a tertiary chloride, characterised by the high mobility of the 

 chlorine atom and by the ease with which hydrochloric acid is split off and camphene 

 is formed. The low stability of the chloride is connected with this fact. In storing, 

 the hydrochloric acid liberated by scission effects a gradual transformation of the 

 camphene hydrochloride into isobornyl chloride (m. p. 158°, IV). The same process 

 takes place rapidly when camphene hydrochloride is heated to 130 or 140° in a sealed 

 tube, or when it is digested with methylalcoholic or ethereal hydrochloric acid at 

 ordinary temperature. For this reason the so-far applied method of preparing camphene 

 hydrochloride — saturation of the concentrated ethereal or alcoholic solution of camphene 

 with hydrochloric acid and recrystallisation of the resulting product from a methyl- 

 alcohol solution of hydrochloric acid — could only lead to an tsobornyl chloride 

 containing camphene hydrochloride. We further understand why the literature records 



H 2 C CH C(CH 3 ) 2 



H 2 C CH C(CH 3 ) 2 



H 2 C CH C(CH 3 ) 



HC 



CH 2 



I 



HC1 



CCH ; 



CH 5 



H 2 C 



HC1 



C< 



CH< 



CH 



Tricyclene. 



,2V -\L-— -CI 

 CH 



Camphene hydrochloride. 



H 2 C CH CH 2 



H 2 C CH 



C(CH 3 ) 2 



HC- 



CH 3 C- CH 3 



C-CH a 



or 



CH 9 



CH 



HC 



CCH 3 



CH 



(I) Tricyclene. 



H 2 C CH CH 2 H 2 C CH C(CH 3 ) 2 



H 2 C CH 



CH 2 



C(CH 3 ) 2 



CH 2 



H 2 G^J^_^C< H 2 C 



C^CH 3 CH 



(II) Compound with bivalent carbon (III) Isocamphane 



atom, not capable of existence. 



CHCHj 



C(CH 3 ) 2 

 H 2 C^J^^CHC1 

 ^C-CH 3 



(IV) Jsobornylchloride. 



*) The constitution of this dibromide is not quite certain yet. 



-) Cf. Report 1916, 119. 



