Under the reaction condition (acidic, basic) the coupling reaction of aryl diazonium chloride with aniline is carried out?

Explanation

Under strongly basic conditions, benzenediazonium chloride is converted into diazohydroxide/diazoate both of which are not electrophilic and hence do not couple with aniline.
`C_(6)H_(5)-overset(+)(N)-=NC l^(-)+OH^(-)hArr underset("Diazohydroxide (does not couple)")(C_(6)H_(5)N=N-OH) overset(NaOH)hArr underset("Sodium diazoate (does not couple)")(C_(6)H_(5)-N=N-O^(-)Na^(+))`
On the other hand, in highly acidic conditions, aniline gets converted into anilinium ion. as a result, aniline is no longer nucleophilic acid hence will not couple with diazonium chloride. therefore, the reaction is carried out under mild conditions, i.e., pH 4-5.
`underset("Aniline")(C_(6)H_(5)NH_(2))+H^(+) to underset("Anilinium ion (does not couple)")(C_(6)H_(5)-overset(+)(N)H_(3))`