Isolation of 3-amino-4-nitrobenzyl acetate: evidence of an undisclosed impurity in 5-amino-2-nitrobenzoic acid

Abstract

Yellow crystals of the title compound 3-amino-4-nitrobenzyl acetate, C9H10N2O4, were isolated from the reaction of acetic anhydride with (5-amino-2-nitrophenyl)methanol, prepared from reduction of commerically available 5-amino-2-nitrobenzoic acid with borane–THF. The molecule is essentially planar (r.m.s. deviation = 0.028 Å). The molecules are linked by intermolecular N—H...O hydrogen-bonding interactions between the carbonyl and amine groups, forming a zigzag chain along theb-axis direction lying in a plane parallel to (-102). The chains are stacked along thecaxis by π–π interactions [centroid–centroid distances = 3.6240 (3) and 3.5855 (4) Å]. A strong intramolecular N—H...O hydrogen-bonding interaction is observed between the nitro group and the amine group [2.660 (2) Å].