Naphthalene-1,3,5,7-tetrasulfonic acid
[6654-67-7]. C10H8O12S4, Mr 448.4, has
no technical importance although it is easily
obtained as the end product of the oleum sulfonation of naphthalene, along with the 1,3,7-trisulfonic acid. In the latter, unlike the 1,3,5-
and 1,3,6-trisulfonic acids, direct entry of a
fourth sulfonic acid group does not occur.