40 PROCEEDINGS OF THE AMERICAN ACADEMY. 



noxy-/3-bromcrotonolactone could easily be made by the reduction of 

 its bromanhydride. 



The mucophenoxybromylbromide was not described by Hill and 

 Stevens, but we found that it could be made without difficulty, in 

 nearly theoretical quantity, by the action of phosphorous tribromide. 

 We used but little more than one molecule of the tribromide to three 

 molecules of the acid, and heated at 100°. When the liquid product 

 became turbid with the separation of phosphorous acid, we added cold 

 water with constant shaking. The bromide immediately separated in 

 a granular form, and could be recrystallized from small quantities of 

 alcohol. It formed fine concentrically grouped needles, which melted 

 at 95-96°. 



0.2363 grm. substance gave 0.2656 grm. AgBr. 



Calculated for C 4 H(0C 6 H s )Br 2 2 Found. 



Br 47.90 47.82 



Mucophenoxybromylbromide is readily soluble in ether, chloroform, 

 or benzol, readily soluble in hot alcohol, more sparingly in cold, and 

 sparingly soluble in ligroin. With alkalies in alcoholic solution it 

 gives a yellow color. The reduction of this body to the correspond- 

 ing lactone is slowly but completely effected by stannous chloride and 

 hydrochloric acid at ordinary temperatures, if a little alcohol be added 

 at the same time to facilitate solution. We have found it more con- 

 venient, however, to use zinc dust and acetic acid. Since the lactone 

 is almost insoluble in dilute acetic acid, and an excess of zinc dust 

 apparently does no harm, we suspended the bromide in twice its 

 weight of glacial acetic acid (99.5 per cent), and slowly added with 

 careful cooling an excess of zinc dust. After standing; for several 

 hours, the reduction is complete, and the addition of water to the fil- 

 tered solution throws down a beautifully crystalline substance, which 

 may be recrystallized from alcohol. The product thus obtained proved 

 on analysis to have the composition of a phenoxybromcrotonolactoue. 

 The weight of the lactone as precipitated by water was 80 per cent of 

 the theoretical amount. 



T. 0.3929 grm. substance gave 0.6796 grm. C0 2 and 0.1008 grm. H 2 0. 

 II. 0.1906 grm. substance gave 0.1410 grm. AgBr. 



Found. 

 I. II. 



47.18 

 2.85 



31.48 



