A trinitro compound, 1,3,5-tris-(4-nitrophenyl)benzene, on complete reaction with an excess of Sn/HCl gives a major product, which on treatment with an excess of NaNO₂/HCl at 0°C provides P as the product. P, upon treatment with excess of H₂O at room temperature, gives the product Q. Bromination of Q in aqueous medium furnishes the product R. The compound P upon treatment with an excess of phenol under basic conditions gives the product S.
The molar mass difference between compounds Q and R is 474 g mol^–1 and between compounds P and S is 172.5 g mol^–1.