BENZYL PHOSPHINES AND THEIR DERIVATIVES. 553 



The compound which they name phenyl-diphospho-sulpho-carbamic acid dissolves in 

 alkalies, and is reprecipitated unchanged on the addition of an acid. Its discoverers do 

 not mention any other substance as being formed at the same time analogous to the 

 crystalline body which we obtained. 



We cannot be at all certain of the composition of either of the two substances ob- 

 tained by us. As regards the crystalline product, the analytical results agree fairly 

 well with the formula (C 7 H 7 ) 2 P 2 H 2 S2, but we did not obtain it in our experiments on 

 the direct action of sulphur on the phosphine, as we should have done in all probability 

 if the above formula were correct. It was produced in too small a quantity for further 

 investigation. With respect to the viscous product, we cannot believe that it is 

 analogous to the phenylated body, for it has no acid properties, and the analytical 

 results are not sufficiently in accordance with the formula. For the present we remain 

 in doubt as to the nature of the substances. 



Action of Sulphuric Acid on Monobenzyl Phosphine. — If sulphuric acid (con- 

 centrated) is added to the phosphine cautiously, and the mixture kept cold, it solidifies 

 to a crystalline mass ; but if it is not cooled a violent action soon occurs, and sulphurous 

 anhydride is evolved in abundance. It may be inferred that the phosphine forms a 

 crystalline sulphate which is very unstable, and probably decomposes into benzyl 

 phosphinic acid and sulphurous anhydride. 



Attempts to obtain the sulphate for analysis were unsuccessful. 



Action of Chloracetic Acid on Monobenzyl Phosphine. — Three separate experiments 

 were tried, with similar results in each case. When equivalent quantities of the phos- 

 phine and chloracetic acid are mixed no action occurs, but some of the acid dissolves. 

 On gently warming the mixture the whole of the acid dissolves, but separates out again 

 on cooling. If the two substances are heated in a sealed tube at 120° for some hours, a 

 dark brown viscous mass results, and on opening the tube pressure is noticed, due to 

 carbonic anhydride. The product undoubtedly contains chloride of acetyl, for it has its 

 very characteristic odour, and fumes in moist air. On removing it from the product by 

 shaking the latter with ether, and then treating the residue with water, a strongly acid 

 solution results, while a little tarry matter remains undissolved. On neutralising the 

 acid solution with baryta and then warming, a crystalline salt is precipitated. This we 

 submitted to analysis (after recrystallisation), and found it to consist of benzyl phosphina.te 

 of barium. 



Analysis. 



. 4794 ( lost at 110° C. 0047 H 2 = 9"80 per cent. 



t gave 03189 BaS0 4 = 0-1875077 Ba = 3911 



Obtained. Calculated for (C 7 H 7 )P0 3 Ba,2H 2 



Barium, .... 3911 3994 



Water, .... 980 1049 



We think that the main course of the reaction must proceed as follows : — 



C 7 H 7 PH 2 +3CH 2 C1.C0 2 H = C^PHA+SCH .COC1 . 



