152322-41-3 3735-97-5 4-06-00-01320 (Beilstein Handbook Reference) 4-Nitrophenyl 2-propylmethylphosphonate BRN 2220854 Isopropyl p-nitrophenyl methylphosphonate Phosphonic acid, methyl-, 1-methylethyl 4-nitrophenyl ester (9CI) Phosphonic acid, methyl-, isopropyl p-nitrophenyl ester p-Nitrophenyl isopropyl methylphosphonate