1226-48-8 4-11-00-00272 (Beilstein Handbook Reference) 4-Methylbenzenesulfonic acid 2-nitrophenyl ester AI3-03740 BRN 2703166 Benzenesulfonic acid, 4-methyl-, 2-nitrophenyl ester o-Nitrophenyl tosylate p-Toluenesulfonic acid, o-nitrophenyl ester