A process for nitration of C6H6 [71-43-2] with continuous removal of H2O formed in the process (by azeotropic distn. with C6H6) using the reaction heat was described in which the H2SO4 catalyst thus remained undild. and did not need to be regenerated. Requirements for minimizing HNO3 losses and keeping the HNO3 concn. to a min. in the mixed acid were discussed. [on SciFinder (R)]