PROFESSOR LETTS ON PHOSPHORUS-BETAINES. 323 
It is quite conceivable that three bodies can exist having the composition of 
hydrobromate of triethyl-phosphorus-betaine. 
The constitution of these three may be represented by the formule— 
if, 1G 
2 gb Br 
(CH) = PC (CH HPC 
CH,—COOH, OOC—CH,, 
Hydrobromate of triethyl- Aceto-bromide of 
phosphorus-betaine. triethyl-phosphine. 
1. 
H 
(CH)),PSC 
OOC—CH.,Br , 
Bromacetate of triethyl- 
phosphine. 
No. II. would probably give no platinum salt, whereas No. IIL, if it gave 
any, would give the chloroplatinate of triethyl-phosphine. No. III. would pro- 
bably give no bromide of silver on treating its solution with nitrate of silver. 
It occurred to the author that the action of caustic potash would decide 
between II. and III. For if it reacted with them at all, the reaction would 
probably be as follows :— 
Br 
(IL) (CH,)=PC + 2KHO = (C,H,,=P=0 +CH,—COOK+KBr+H,0. 
00C—CH, 
H 
(II1.) (CyH,) =P + KHO = (C,H,),=P+CH,Br— COOK +H,0. 
0OC—CH,Br 
With II. potash would react to give oxide of triethyl-phosphine, acetate of 
potassium, bromide of potassium, and water ; whilst III. would give with the 
same reagent triethyl-phosphine and bromacetate of potassium (or glycollate 
and bromide of potassium). 
It was resolved, therefore, to submit the product of action of bromacetic 
acid on triethyl-phosphine to treatment with caustic potash. 
Action of Caustic Potash.—18 grms. of triethyl-phosphine were dropped 
slowly into 20 grms. of bromacetic acid in the apparatus already mentioned. 
The product was heated to 100° for about twenty minutes ; it became brown, 
and a few bubbles of gas were evolved ; on standing it solidified. It was then 
dissolved in chloroform, and a large excess of dry ether added—sufficient to 
precipitate the product in the crystalline state. The mixture of chloroform 
and ether was poured off from this, and it was then well washed with dry 
ether, and the last traces of ether removed by gentle heating. 
