PHENYL MAGNESIUM BROMIDE ON CAMPHOR. CREIGHTON. 595 



4.8 g., of cleaned mag-nesium ribbon contained in a round bot- 

 tomed flask, to which was fitted a retiux condenser. It is most 

 -essential that the magnesium ribbon be perfectly free from 

 oxide. When about ^ of the halide had been added, the fiaslc 

 became warm and a vigorous reaction set in, making it neces- 

 sary to cool the flask with running water, lest too great heat 

 -should cause decomposition. 



The calculated amount (17 g.) of camphor, the camphor 

 -and halide reacting molecule for molecule, was dissolved in 1? 

 times its weight of ether and allowed to drop slowly into the 

 magnesium halide. This compound was contained in a round- 

 bottomed flask fitted with a return condenser. The mixture was 

 kept at (30 °C. The contents of the flask were allowed to stand 

 over night, the reaction being a gradual one. Xext morning the 

 mixture was ponred on crushed ice, containing a small excess 

 of dilute hydrochloric acid to dissolve the precipitated 

 Mg (OH)o, and the new product separated out as an oily yellow 

 liquid. These equations illustrate the reactions taking place: — - 



/OMgBi 



C6H5MgBr + C<,Hi6'J = = CqHieC^ 



OMgBr /OH 



CqHieC +2H.,0 = CqHieC; - Mg(OH.,) r HI!r 



CeMs ' -^ CV.H,, 



The oil ^vas separated from the rest, of the mixture and 

 shaken up five times with sodium aci<l sul[ihite to remove any 

 ketone that had not been acted upon. It was then washed 

 with water to remove the sodium acid suliihite and dehydrated 

 over calcium chloride. 



The oil was then heated in a distillinf: flask, and at 

 205-210°C. a vapour was given off, which on cooling, solidified 

 in the condenser to a white mass. This proved to be camphor. 

 The flask was allowed to cool and the contents heated in vacuo, 

 a pale yellow oil distilling over at ]50"C. 



