Significantly better yields were achieved in Mizoroki–Heckreactions using 4-phenoldiazoniumsalts instead of their O-alkylated analogues under otherwise identical conditions. We found that a one-flask deacetylation–diazotation–precipitation sequence starting from paracetamol or acetanilides derived thereof provides a convenient access to the required diazonium tetrafluoroborates. The utility of these