Synthetic Methods and Reactions, XVI. The Nitramine Rearrangement ofN-Nitrodimethylanilines. A Novel Route for the Conversion of 3-Nitro-o-xylene into 4-Nitro-o-xylene

Stacking and N—H...O interactions in 2,3-dimethyl-6-nitroaniline

“…In all cases, similar prismatic crystals of (I) were obtained. The analytical data were in good agreement with those reported in the literature (Courtin & von Tobel, 1980;Olah et al, 1976;Divekar & Vining, 1964). All C-bonded H atoms were placed in calculated positions and were refined as riding on their parent C atom [C-H = 0.93 (aromatic) and 0.96 Å (methyl), and U iso (H) = 1.2U eq (C arom ) and organic papers…”

ipso-Nitration of 4-iodo-o-xylene

“…5 Nitration of 4-IOX was run under several sets of conditions (Table I) and products were analyzed by GLC. The desired 4-NOX (2) was formed in each case in yields ranging from 6 to 13%; however, ordinary nitration (nitrodeprotonation) to give 5-iodo-3-nitro-o-xylene (4) and 4-iodo-5-nitro-o-xylene10…”

“…Recent approaches have included clathration of the aromatic to induce additional steric influence on selectivity1 and rearrangement of the undesired initial product of electrophilic attack on the aromatic to give the desired one. 2 The nitration of o-xylene typifies the problems encountered in attempting to alter product isomer distribution. A wide variety of nitrating agents have been found to give a 4-nitro-o-xylene (4-NOX) to 3-nitro-o-xylene (3-NOX) product ratio which could not be made to exceed 3:1.2 Since 4-nitro-o-xylene is a useful reagent for further reactions, increasing this ratio without increasing the extent of side reactions would provide a higher yield of a less contaminated material.…”