40. Solving a chemistry problem

18. In FS 42-2709-98 for novocaine, in the "Authenticity" section, it is said that a solution of 0.05 g of the drug in 2 ml of water gives a characteristic reaction to primary aromatic amines with the formation of an orange-red color, turning into cherry red. Give a method for determining the authenticity of novocaine, write the equations of chemical reactions. Can this reaction be carried out in a neutral or slightly acidic medium?