(473 ) 
triethylbenzene, and sym. durene appear to be diacetylised ; from the 
experiments it appears that at least two mols. of the catalyzer are 
wanted (V. Meyer, B. 1895 p. 3212; B. 1896 p. 846; B. 1896 p. 
2564; H. Wem, B 1897 p. 1285). 
VY. The catalyzer combines but little or not at all with the chloride 
(A) or the benzene derivative (B) combines only with the formed product. 
When this is a molecular compound (as in the cases known up to the 
present) at least one mol. will be required for one mol. of the chloride. 
I have found that one mol. of carbon tetrachloride exactly requires 
the molecular quantity of aluminium chloride for the formation of 
triphenylmethane chloride 
CCl, + 3C,H, + AICI, = 3HCI + (C,H),CCI. AICI,. 
S,Cl, and SCI, also require one mol. of the catalyzer when being 
condensing with benzene. 
The behaviour of sulphur itself towards benzene is very interesting 
in this respect; from an investigation, the details of which will be 
published elsewhere, it appears that this condensation must be repre- 
sented by the following scheme : 
S; + 6C,H, + 3AlCl, = 2(C,H,),S. AICI, + (C,H,)S,. AICI, + 4H,S 
diphenylsulphide thianthrene 
For one mol. of sulphur, three mols. of the catalyzer are absorbed; 
the element itself does not combine with aluminium chloride. 
As stated above we have only mentioned the cases where no 
secondary actions occur or where these may be greatly prevented. 
In a number of syntheses this is very difficult to realise particularly 
where we start from chlorides where the carbon atom which carries 
the chlorine atom is also combined with hydrogen atoms (Recueil 
XXII p. 306), or where hydrogen and chlorine oceur near adjacent 
carbon atoms. ((Moungyrat, Bull. Soe. chim [8] 17 p. 797; [3] 19 
p. 179, p. 407 and p. 554). 
To this belong all the syntheses of the homologues of benzene 
where we also have the circumstance that the more alkyl groups 
enter into the benzene, the more readily it will be decomposed by 
aluminium chloride ; the quantities of aluminium chloride required there- 
fore become larger and vary in each individual case. In order to get 
a better insight in the actual catalytic action of aluminium chloride 
these last reactions will furnish in my opinion, a less suitable ma- 
terial than the first five categories which I have mentioned. These 
will have to be submitted to a systematic and, if possible, also 
quantitative research. 
I have been engaged for some time in experiments in this 
direction, which will be published from time to time. 
Assen, Dee. 1904. Chem. Lab. H. B. S, 
