Diazotisation of 2-aminophenol-N-methyl-4-sulphonamide with 1-acetylamino-7-naphthol

I have been trying to make diazonium salt of 2-aminophenol-N-methyl-4-sulphonamide in $ce{HCl}$ with $ce{NaNO2}$ solution. Then I want to make coupling with 1-acetylamino-7-naphthol. Since 1-acetyl-7-naphthol is soluble in caustic alkaline solution, so I made a clear solution of it. Now, when the diazonium salt is formed (verified on SI strip and then made negative with sulfamic acid); I started addition of alkaline solution of 1-acetaylamino-7-naphthol. Slow addition of this solution at temperature below $pu{10 ^circ C}$. Both the materials remained unreacted. 1-acetylamino-7-naphthol was precipitates back.

Then I tried reverse, addition of diazonium salt into the alkaline solution of 1-acetylamino-7-naphthol. But the results were same. Kindly advice for this problem.