HILL AND COUNELISON. — CROTONOLACTONES. 31 



a-phenylamidocrotonolactone is very sparingly soluble even in boil- 

 ing water. It dissolves quite readily in boiling alcohol, more spar- 

 ingly in cold, and very sparingly in hot benzol or chloroform ; in 

 ether, ligroin, or carbonic disulphide, it is nearly insoluble. It is 

 readily soluble in hot glacial acetic acid, and crystallizes on cooling in 

 feather-formed aggregations of branching needles. The melting point 

 of the substance varies somewhat according to the rapidity with which 

 it is heated ; but with proper care to avoid long heating it was found 

 to melt quite sharply at 217-218°, although decomposition ensued on 

 further heating. Material made from the a-chlor- and a-bromlactones, 

 as well as by the reduction of the phenylamidobromlactone, showed 

 identically the same behavior on heating, and when tested side by side 

 in the same bath melted at the same temperature. The body dis- 

 solves readily in hot concentrated hydrochloric acid, but aniline seems 

 to be formed at once. In hot alkaline solutions it dissolves somewhat 

 more readily than in water, and if such a hot solution is quickly 

 cooled it separates apparently unchanged. On longer heating decom- 

 position sets in. A solution of the body in hot dilute baric hydrate 

 was boiled for a short time and distilled. The distillate contained 

 aniline in abundance, as was shown by the formation of tribromaniline 

 melting at 118-119°. At the same time baric carbonate had been 

 precipitated, and in solution was found a barium salt which was ex- 

 tremely soluble in water, was precipitated by alcohol from the con- 

 centrated aqueous solution in an amorphous form, and was left as a 

 brownish varnish upon evaporation. 



Reduction of the o/3-Dibromcrotonolactone to 

 Crotonolactone. 



When dibromcrotonolactone is heated to 100° with dilute sulphuric 

 acid and granulated zinc, it is rapidly reduced, and at the end of sev- 

 eral hours the reduction is complete. It was easy to prove by quan- 

 titative determinations that all the bromine of the original substance 

 had been converted into hydrobromic acid, and the behavior of the 

 solution toward decinormal potassic hydrate also showed that it con- 

 tained a lactone in nearly theoretical quantity. AVe found it practi- 

 cally impossible to extract the lactone from aqueous solution, and we 

 therefore distilled this solution in a current of steam. The distillate 

 which we obtained was feebly acid, but it also contained a small quan- 

 tity of a lactone, which, however, we found by titration to be relatively 

 large in proportion to the free acid. The amount of free acid varied 



