Crossword-Solution: BENZIDINE 9 letters, 1 clue 🏆 scrabble score: 21

These amido compounds, of which aniline, toluidine, benzidine, naphthylamine are familiar examples, are characterised by containing the molecular group NH{2}, which radicle is built up of the two elements nitrogen and hydrogen.

Then a bath is prepared by diazotising paranitroaniline, benzidine, metanitraniline, dianisidine, etc., or by using the ready diazotised preparations which are now on the market, Nitrazol C, Azophor red P N, Azophor blue P N, etc., and immersing the dyed cotton in this bath.

When these are reduced by acid reducing-agents, they become converted into diamido-bases which are known as benzidine and tolidine respectively.

Thus diazotised benzidine and tolidine combine with salicylic acid to form valuable yellow azo-dyes known as "chrysamines." The dyes of this class obviously contain two azo-groups.

Tolidine has been found to give better colouring-matters in most cases than benzidine, and it is scarcely necessary to point out that an increased demand for the nitrotoluene from which this base is made is the necessary consequence of this discovery.