

1 uur 



2 „ 



3 „ 



4 „ 



^ „ 



7 .. 



Benzhydrole 

 formed 



Remarks 



3.37 gr. 



3.45 „ 



3.41 „ 



3.4 „ 



3.2 „ 



3.3 „ 



3.4 .. 



The residue on evaporation was 

 odourless and melted at 68° hence 

 contained no benzophenone and diphe- 

 nylmethane. 



The insoluble part contained 1.55 

 grams of pinacone. 



Preliminary experiments, where the 

 solution after boiling was left for 24 

 hours. After filtering, the residue was 

 washed with cold alcohol. 



The insoluble part contained 1.6 

 grams of pinacone. 



3. Reduction in a faintly acid meditim. 



A. With zinc dust. 



After it had been ascertained that no appreciable cliange had 

 taken place on boiling benzophenone with 80 7o alcohol and zinc 

 dust for 6 hours, the operation was repeated in a current of carbon 

 dio.vide. 



After boiling 10 and 12 hours 4.19 and 4.00 grams of residue 

 were obtained on evaporation ; this however, melted just below 48° 

 and had the usual properties of benzophenone. The I'emaining of 

 the 5 grams was benz pinacone. 



On again subjecting the residue a few times to the same process 

 (in order to concentrate hydrole formed eventually) the quantity 

 became less, namely 2.9 and 1 gram, but it remained benzophenone. 

 The quantity of the product insoluble in 80"/^ alcohol increased, 

 it was pinacone, but not very pure. 



With zinc dust in a very faintly acid medium the reaction there- 

 fore proceeds very slowly and with exclusive formation of pinacone. 



This same result was also obtained when instead of carbon dioxide 

 ammonium chloride was taken. 10 grams of zinc, 3 grams of NHX'l 

 and 50 cc. of 80% alcohol weie chosen for 5 grams of benzophejione. 



The operation here had to be modified somewhat because the 

 residue on evaporation contained zinc and nitrogen; it was boiled 

 with hydrochloric acid (1 part of acid 1.19 — 1 part of water), 

 washed and dried. 



After boiling for 372, 6 and 12 hours we obtained as a purified 

 residue: 2,22, 1.87, and 0.99 gram of a sul)stancc melting below 48° 

 and having a strong odour of benzophenone. 



The insoluble part was a not very pui-e pinacone; after extraction 

 with benzene and evaporation it melted at 170°. 



