( 683 ) 



compounds will yield a large quantity of halogenised by-products on 

 reduction with tin and hydrochloric acid. It would be necessary to 

 know something more about the reduction velocity of the nitrocom- 

 pounds ') (and of the intermediaiy formed hydroxylaminederivatives), 

 and about the intramolecular conversion velocities of the halogen- 

 phenylaniines. 



It is known, for instance, that o-nitrotoluene gives a large amount 

 of chlorinated by-product on reduction with tin and hydrochloric 

 acid ^). The o-tolylhydroxylamine formed as intermediate product is, 

 therefore converted here into 5-chlorotoluidine, and the reduction ex- 

 periments of GoLDSCHMiDT ') on 0-nitrotoluene are in agreement with 

 this. GoLDSCHMiDT has shown that, with increase of the temperature 

 the reduction velocity also increases, whilst an elevation of temperature 

 also increases the conversion velocity of the halogenphenylamines. 

 It now appears that this last reaction is the most strongly accelerated, 

 for the amount of halogenised by-products increases with elevation of 

 the temperature *). 



Resume'. It has been shown that the reduction of nitrobenzene with 

 tin (or Sn CI,) and hydrochloric acid may be carried out in such a 

 manner that ^^-chloroaniline occurs as the main product. The cause 

 of this must be explained by the fact that, in the reduction of 

 nitrobenzene, phenylhydroxylamine occurs as an intermediate product. 

 As on reduction of all aromatic nitrocompounds, hydroxylamine 

 derivatives are formed as intermediate compounds, we shall generally 

 notice on reduction of such nitrocompounds with tin and hydrochloric 

 acid, besides amidocompounds, also halogenised amidocompounds 

 (with halogen atoms o- or p- in regard to the NH, group), whilst 

 the quantity of these two last substances will be dependent on the 

 conditions under which the reduction is carried out. In some cases 

 no halogen atoms are introduced, but they are even eliminated from 

 the benzene core '). 



I hope to record more fully further experiments in the Recueil 

 later on. 



Amsterdam, January 1906. 



1) See the note on the preceeding page. 



2) Beilstein and Kühlberg, Ann, 156, 81. Hollem an and Jungius, Chemisdi Week- 

 blad II. 553. 



3) 1. c. 



*) PiNNOW, 1. C. 



6) Recueil 24, 320. 



48 



Proceedings Royal Acad. Amsterdam. Vol. VIII. 



