and anilines to give the triazenes. Azo couplings are achieved with quantitative yields by cautious co-grinding of solid diazoniumsalts with beta-naphthol and C-H acidic heterocycles, such as barbituric acids or pyrazolinones. Solid diazoniumsalts may be more easily applied in a stoichiometric ratio for couplings in solution. Co-grinding of solid diazoniumsalts with KI gives quantitative yields of