( 775 ) 



standing' of tlie inoclianisni of the HF/KMANN-rearmngement. Tliey 

 prove tlial lliis iinporlani (raiisforniation is inosi decidedl}' a real 

 inti'ainolei'ular rearrangement, wliicli may occni- in some cases with 

 the oxime, Itnl in the majority of cases with derivatives in which, 

 instead of jjie OH-gronp, another negati\e groiij) or a halogen has 

 been attaciied lo the nitrogen. In that case the change from II into 

 III represents the actnal I'earrangement. 



AuwKRS and Czerxy have already j)ointed ont that the above rearran- 

 gement caused by distillation deserN-es the closest attention. They are 

 of opinion thai this observation leads to Ihe view that the Beckmann- 

 rearrangement is a calalytical process which is in accord with 

 Bkckmann's own ideas. Bnt is it permissible to speak of a catalytic 

 process when the catalyzer is ^vanting? And do not Auwers and 

 CzERNY withdraw their o^^'n statement when they say that "es sich 

 vielmehr handelt iim die directe üeberführnng eines weniger stabilen 

 System in ein stabileres?" 



The BECKMANN-reai-rangement has not, up to the present, been 

 subjected to a dynamical inxestigation. Such a study is not i-endered 

 less desirable or less important by the fact that, as a rule, the 

 rearrangement of the intermediate jtroduct and not that of the oximes 

 themselves will be investigated. 



The oxime which has been studied in the lirst place is aceto- 

 phenonoxime of which only one form is known and which quantita- 

 tively passes into acetanilide. Its configuration is therefore: 

 C,H.— C— CH, -^ C,H,. HN. COCH3. 



II 

 HON 



The rearrangement, which Bec;kman'N found to take place under 

 the i])thience of concentrated sulphuric acid was studied in the lii'st 

 place. Before starting it was necessai-y to work out an analytical 

 method allowing the (pumtitative determination of the resulting anilid 

 in I lie presence of tlie unchanged oxime. After several ])reliminary 

 ex[)eriments it was found that the anilide formed on adding water 

 was completely hydrolyzed by boiliiig for a few houi's and that the 

 acetic acid could then be distilled olf and titrated; the excess of 

 oxime did not interfere. We have in consecpienco determined the 

 velocity with which the aiiilide Avas formed. In cai-rying out the 

 experiments 2.5 grams of the oxime were dissolved in 50 or 1ÜÜ cc. 

 of sulphuric acid, previously heated to the temperature at which the 

 experiment was made (60"^ or 65°) and at detinite periods a certain 

 quantity was pipetted off from the bottle (which was placed in a 

 thermostat) and analysed. 



