Hi!. I carried out a reaction for introducing 2 formyl groups into a phenol on the orto positions. Firstly to a solution of 1 mole of my phenol in 50 ml of acetic acid i added 2 moles of hexamine and 10 moles of p-formaldehyde. After stirring the mixture and heating it for 12 hours, Con. Sulfuric acid was added and heated again for half an hour.Then the product was precipitated in water. The point is, I would like to know the role played by p-formaldehyde in this reaction.