HILL AND CORNELISON. — CROTONOLACTONES. 25 



The /3-bromcrotonolactone is readily soluble in alcohol, chloroform, 

 benzol or carbonic disulphide. It is decidedly less soluble in ether, 

 and very sparingly soluble in ligroin. From small quantities of 

 alcohol it crystallizes in colorless clustered prisms, from ether by slow 

 evaporation in lai'ge transparent six-sided plates. It is quite readily 

 soluble in hot water, and as the hot aqueous solution cools it separates 

 in clear obliquely truncated prisms. It melts at 58°, and boils under 

 a pressure of 18 mm. at 140°. It distils with steam, although with 

 some difficulty. Aqueous alkalies dissolve it with the formation of a 

 deep yellow color, and the solution then contains an alkaline bromide. 

 In dilute alcoholic solution aniline also removes bromine, but forms 

 at the same time a dark-colored viscous oil, from which we have been 

 able to isolate no crystalline product. 



Action of Bromine. 



/3-Bromcrotonolactone is but slowly attacked by bromine in the cold. 

 If one molecule of bromine is added to the powdered lactone, a clear 

 deep red solution is soon obtained, but the color fades so slowly that 

 several days are required to complete the reaction at ordinary temper- 

 atures. On opening the tube a small quantity of hydrobromic acid 

 escaped, but the weight of the crystalline product was substantially the 

 same as that of the materials employed. After several recrystalliza- 

 tions from alcohol an analysis also showed that the substance had been 

 formed by the addition of bromine. 



0.2965 grm. substance gave 0.5175 grin. AgBr. 



Calculated for C 4 H 3 Br 3 0,. Found. 



Br 74.30 74.27 



This body, which from the mode of its formation must be the a/3o-tri- 

 brombutyrolactone, is readily soluble in alcohol, ether, benzol, carbonic 

 disulphide, or chloroform, but is more sparingly soluble in ligroin. 

 From alcohol it is deposited in large, well formed, brilliant prisms, 

 which melt at 63-64°. On boiling with water a part distils un- 

 changed, but decomposition soon sets in, carbonic dioxide is evolved, 

 and hydrobromic acid is formed. If the /3-bromcrotonolactone is 

 heated to 100° with one molecule of bromine, the color of the bromine 

 soon disappears, but at the same time hydrobromic acid is formed in 

 considerable quantities. With an excess of bromine at 100° mucobro- 

 mylbromide is formed in abundance. The product which we obtained 

 melted at 56-57°, gave in alcoholic solution a deep blue color with so- 

 dic carbonate, and when heated with water yielded mucobromic acid. 



