It is better to use mercury nitrate, given that very small amounts are needed for synthesis, the costs will be insignificant. If you have difficulty buying concentrated sulfuric acid, you can evaporate water from a 65 percent solution. Glass demijohn is not heat-resistant, during an exothermic reaction, the vessel can burst and cause a lot of trouble. It is best to put the first syntheses in small flasks with minimal loads of phenylnitropropene, and with increasing experience, gradually increase the load of the precursor. The video clearly shows the process under ideal conditions, but in this reaction there are problems, and only experience helps to find solutions for them.