Certain New Derivatives in the Aromatic Series. 183 



PART II. 



practicaIj work on the new derivatives. 



I. The use of the three compounds, benzidine, tolidine, and anis- 

 idine, suggested the thought, that if other compounds of similar 

 character — that is, bearing amido groups, possessing if possible a 

 polycyclical structure, and of high molecular weight — were to be 

 applied, perhaps dyes would result which would be as good or 

 better. 



Fluoren, therefore, was taken in hand. It has the formula, 



Fluoren has never been developed, probably on account of its 

 high price. But in the coal-tar industry, the price of a chemical is 

 never an obstacle which stands in the way of its application in a 

 color for a very long time, as means are eventually found for the 

 more economical manufacture of the desired compound. As, for 

 instance, the alizarine industry, where the anthrachinone was only 

 a chemical curio in museums until its presence in enormous quanti- 

 ties was wanted, when it became as reasonable in cost as could be 

 expected. 



Fluoren, or diphenyl-methane, is found in coal-tar, and can be 

 synthesised by passing diphenyl through hot tubes; or by the dis- 

 tillation of diphenyl-ketone wnth zinc dust; or treating diphenyl- 

 ketone with phosphorous and hydriodic acid ; and also by distilla- 

 tion of phenanthrachinone with lime. 



Fluoren is changed to dinitro-fluoren by adding it to a mixture 

 of equal parts of nitric and glacial acetic acids. The fluoren which 

 was unconverted was separated from the dinitrofluoren by washing 

 with hot alcohol; then it was crystallized from glacial acetic acid. 

 Fluoren has a melting-point of 112; the dinitro-derivative melts at 

 199-201. 



This dinitro-fluoren was changed to the diamido derivative by 

 the addition of tin to the acid solution. The formula of the diamido 

 fluoren is, 



C«H3(NK,K 



>CH„. 



C,H,(NH,/ 

 Annals N. Y. Acad. Sci., VIII, April, 1894.— 13 



