When an primary aromatic amine is treated with `NaNO_(2)+HCI` at `0^(@)-5^(@)C`, a diazonium salt is formed and the reaction is called diazo reaction. In this reaction mineral acid must be added to prevent the coulping reaction of diazonium salt with excess of aryl amine. diazonium salt is highly in the synthesis of number of coloured dyes.
When 2,4-dinitrophenol react with `NaNO_(2)+HCI` at `5^(@)C` followed by reaction with anisole, a coloured compound is formed which can be given as:
A.
B.
C.
D.
