HILL AND CORNELISON. — CROTONOLACTONES. 23 



The a-iod-/3-bromcrotonolactoue is quite readily soluble in benzol or 

 chloroform, more sparingly soluble in ether, carbonic disulphide, or 

 lio-roin. It dissolves freely in boiling alcohol, and as the solution cools 

 it is deposited in quite large, oblique, colorless prisms, which gradually 

 change color on exposure. With steam it distils with difficulty. The 

 melting point of most preparations of this substance we have found to 

 be constant at 118-119°. Still we were frequently unable to raise by 

 recrystallization alone the melting point of material which melted at 

 too low a temperature, and on one occasion a preparation made in the 

 usual way melted one degree higher at 119-120°. Toward aqueous 

 alkalies this substance behaves like the corresponding bromine deriva- 

 tive, an alkaline iodide being formed in the decomposition. Concen- 

 trated nitric acid or bromine water on boiling liberates iodine. When 

 heated with one molecule of dry bromine in sealed tube at 100°, 

 iodine is also liberated, and but a small quantity of hydrobromic acid is 

 formed. With aniline in dilute alcoholic solution it yields the a-phe- 

 nylamido-/S-bromcrotonolactoue, which has already been described, al- 

 though not quite as smoothly as the dibromlactone, since dark-colored 

 viscous products, which we have not further examined, are formed at 

 the same time. On reduction with zinc dust and glacial acetic acid, 

 the /3-bromcrotonolactone melting at 58°, which we shall presently 

 describe, was formed. After dilution with water the acid solution was 

 extracted with ether, the ethereal extract washed with a dilute solution 

 of sodic carbonate, and the crystalline residue obtained by the evapo- 

 ration of the ether recrj^stallized several times from small quantities of 

 alcohol. The body thus obtained had the properties of the /3-brom- 

 crotonolactone, melted at 57-58°, contained but an unweighable trace 

 of iodine, and gave on analysis the required percentage of bromine. 



0.2078 grm. substance gave 0.2407 grm. AgBr. 



Br 



When the iodbromcrotonolactone was boiled with hydriodic acid the 

 separation of iodine soon ensued. After long boiling with the addi- 

 tion of red phosphorus, although traces of volatile products, which 

 had the odor of fat acids, had been formed, the main product of the 

 reduction was a viscous oily body, which could be extracted by ether 

 from the diluted solution, but from which we were unable to prepare 

 any material suitable for analysis. With distillable hydriodic acid 

 and red phosphorus in sealed tubes at temperatures below 180° we 



