Propyl p-hydroxybenzoate and methyl p-hydroxybenzoate are two different chemicals with different chemical structures and properties. Propyl p-hydroxybenzoate is a white crystalline powder, insoluble in water and soluble in organic solvents. However, methyl p-hydroxybenzoate is a white crystalline powder with aromatic smell, insoluble in water and soluble in organic solvents.

Therefore, propyl p-hydroxybenzoate and methyl p-hydroxybenzoate cannot be transformed into each other in methanol solution.