BENZYL PHOSPHINES AND THEIR DERIVATIVES. 587 



(1) Monobenzyl phosphine, .... 



(2) Benzyl phosphinous acid, .... 



(3) Benzyl phosphinic acid, 



(4) Dibenzyl phosphine, ..... 



(5) Dibenzyl phosphine oxide (?), (" crystalline oil "), 



(6) Dibenzyl phosphinic acid, .... 



(7) Tribenzyl phosphine, ..... 



(8) Tribenzyl phosphine oxide, .... 



(9) (''Insoluble crystalline body"), 

 (10) A resin containing phosphorus, insoluble in alcohol and ether, but soluble in 



chloroform. 



(C 7 H 7 )H 2 P 



(C 7 H 7 )H 2 P0 2 



(C 7 H 7 )H 2 P0 3 



(C 7 H 7 ) 2 HP 



(C 7 H 7 ) 2 HPO(?) 



(C 7 H 7 ) 2 HP0 2 



(C 7 H 7 ) 3 P 



(C 7 H 7 ) 3 PO 



(C 7 H 7 ) 3 PO 2 0) 



It is not possible for us to say how many of these different substances exist as such in 

 the original product of the sealed tube reaction, and how many are formed in the 

 subsequent treatment to which it is subjected. 



The three phosphines no doubt exist in the original product as hydriodates or 

 hydrochlorates combined with chloride or iodide of zinc, and we think that their produc- 

 tion is of great interest, for hitherto only primary and secondary phosphines have been 

 obtained when an alkyl iodide, oxide of zinc, and phosphonium iodide are heated together 

 under pressure ; whereas we prove that, when chloride of benzyl is substituted for an 

 alkyl iodide, the tertiary phosphine is formed also. 



It is well-nigh impossible for us to say definitely whether the quaternary compound is 



formed as well, for it would certainly combine with chloride or iodide of zinc, and would 



be very troublesome to separate from these substances. But the occurrence of oxide of 



tribenzyl phosphine, after the product of the sealed tube reaction had been steamed and 



treated with potash in a hydrogen atmosphere, is, in our opinion, almost conclusive proof 



that tetrabenzyl phosphonium was orignally present, and had been decomposed by the 



alkali, 



(C 7 H 7 ) 4 PI -(- KHO = (C 7 H 7 ) 3 PO + C 7 H 8 + KI , 



a reaction which occurs with the greatest ease when the two substances are boiled to- 

 gether in aqueous or alcoholic solution. How otherwise could the oxide be produced in 

 quantities so large as those we observed ? 



If we assume that all four phosphorised derivatives are produced, the reaction 

 becomes analogous to that which occurs when a haloid compound of a hydrocarbon 

 radical is treated with ammonia, the only difference being that hydracid (hydrochloric) 

 is liberated in the case of phosphuretted hydrogen, and is found in the gases contained 

 in the sealed tubes. 



Whether the substitution of an alkyl chloride for an iodide is the cause of the pro- 

 duction of a tertiary and (probably) quaternary compound in addition to the primary 

 and secondary phosphines, or whether benzyl behaves differently in Hofmann's reaction 

 from other alkyl radicals, we have not as yet decided. There can, however, be very little 



