4-Methylbenzenesulfonic acid (2-pyridinylmethylene)hydrazide N-oxide 50908-22-0 BRN 1543622 Benzenesulfonic acid, 4-methyl-, (2-pyridinylmethylene)hydrazide, N-oxide NSC 177227 p-Toluenesulfonylhydrazone of 2-pyridinecarboxaldehyde-1-oxide