Abstract
N2O4 was easily impregnated on polyethyleneglycol to give a stable reagent. The polyethyleneglycol-N2O4 (PEG-N2O4) system was used as an effective nitrating agent for the nitration of phenols. Mono- and dinitrophenols can be obtained via direct nitration of phenols in the presence of PEG-N2O4 at room temperature in moderate to high yields.
ACKNOWLEDGMENT
Financial support for this work by the Research Affairs Program of Bu-Ali Sina University, Hamedan, Iran, and the Center of Excellence of Developing of Chemical Methods (CEDCM) is gratefully acknowledged.
Notes
a PEG-N2O4–substrate (0.4 g:1 mmol).
b PEG-N2O4–substrate (1.0 g:1 mmol).
c Isolated yields.
d The yields and times of dinitration are written in parentheses.
e Because of volability of the product, CH2Cl2 was used as eluent for column chromatography.