( 419 ) 
p. 4453), Oxalyl chloride, on heating gently, into CO and COC1, 
(H. Staudingeh Ber. 1909 p. 3566). 
In order to test the above view more closely I have added to 
these examples a few others, my chief object being to demonstrate 
(so as to elucidate the action of the catalyst in the Friedel and Craft’s 
reaction) that, in the first place the chlorine atom is loosened. As 
a rule the chlorine atoms will leave the molecule as such in a few 
instances only; this may be demonstrated, for instance, by gently 
warming C 2 Cl fi with aluminium chloride and it is this cleavage 
which causes no doubt the very complex course of the reaction 
between perchloroethane and benzene. 
Considering that the reaction might proceed more readily if during 
the decomposition stable chlorine compounds such as HC1 could be 
formed, 1 have chosen the following four substances: trimethylacetyl 
chloride, dichloroacetylchloride, chloral and trichloroacet.yl chloride, 
which all contain the more or less overloaded CO-group, so that the 
reaction could be watched by the evolution of the carbon monoxide. 
It is certainly remarkable that, notwithstanding the excess of 
chlorine atoms, tricbloroacetyl chloride is the most difficult to attack. 
A priori, there is not much to say as to the velocity of these 
reactions. The result of this research seems to point out that the 
reaction proceeds particularly smoothly in the case where H and Cl 
atoms are present next to two adjacent C atoms and that in the 
second place the overloading plays a role. 
Of the three other substances the trimethylacetyl chloride is the 
one attacked most readily, whereas the two isomers dichloroacetyl 
chloride and chloral do not show large differences. 
In all cases, however, the reaction takes place in such a manner 
that the movable Cl atom combines either with an H atom or a 
molecule residue, in which case a molecule of carbon monoxide is 
always evolved. 
I. Trimethylacetyl chloride is resolved at 0° according to the 
equation: 
(CH 8 ) 8 CC0C1 = HC1 + CO + CA 
the isobutene is nearly entirely polymerised. 
II. Chloral on being heated gently is decomposed in two directions. 
A CC1 8 C0H = HC1 + CO + CC1 S ± 70—75% 
a nd the CC1 2 residue is polymerised to C t Cl 4 
B CC1 8 C0H = CO -j- CCljH 
a slight resinification cannot be entirely prevented. 
