180 



REPORT— 1902. 



Tsomorphoiis Sidphonic Derivatives of Benzene. — Third Report of the 

 Committee, consisting of Professor H. A. Miers (Chairman), Dr. 

 H. E. Armstrong (Secretary), Dr. W. P. Wynne, and Mr. W. J. 

 Pope. (Drawn xtp by the Secretary.) 



The crystallographic study of the 1:3:5 series, the second of the three 

 series of sulphonic clilorides and bromides to be derived from the 1 : 3- 

 dichloro-, chlorobromo- and dibromo-benzenes examined thus far, has been 

 practically completed by Dr. Jee during the past year. The results are 

 even more striking than those obtained in the case of the 1:3:4 series, 

 as there is evidence that the compounds constitute not merely an i&otri- 

 morphous group, as in the latter case, but an iso^eiramorphous group, as 

 shown in the following table : — 



In this series the dibromobenzenesulphobromide has again been the 

 means of formulating the relationships between the various terms, having 

 been obtained in two distinct polymorphic forms. But in comparison 

 with the 1:3:4 series the order of stability is reversed, the transition 

 temperature becoming lower in passing down the series. 



It is proposed to submit an account of the results obtained in the 

 case of the 1:4: ^(SOaH), 1:3: 4(S03H), and 1:3: 5(S03H) series to 

 the Royal Society in the autumn. 



The third series of the 1 : 3 derivatives, in which the sulphonic group 

 is between the halogens, has yet to be examined. Very great difficulty 

 has been experienced in preparing the necessary material, but methods 

 have now been devised which promise success. Thus diorthobromo- 

 benzenesulphonic acid has been prepared from diorthobromaniline by 

 Gattermann's sulphinic-acid method. Unfortunately, the corresponding 

 dichlor- and chlorobromaniline are not at present available, and therefore 

 other methods of preparing the dichlor- and chlorobrom acid need to be 

 devised. Apparently these will be obtainable from the dimeta-derivatives 

 of aniline. 



A complete series of 1:2: 4(S03H) derivatives has been prepared, 

 and their crystallographic study will now be undertaken. To complete 

 the investigation, so that it shall comprise all the series derivable from 

 the dichloro-, dibromo- and chlorobromo-benzenes, only the 1:2:3 

 (SO3H) series has to be prepared. This, again, i^ a matter of considerable 

 diS^culty, recjuiring special investigation. 



