4-chlorophenol (10
mmol), TBAB, 10 mol % of substrate, nitric acid (70 wt %,
20 mmol), water to make up the nitric acid concentration to
6 wt %, and ethylenedichloride (20 mL), were mixed together
in a 50-mL glass reactor and stirred at 20 °C for 4-6 h.
Reaction progress was monitored by GC. Products were
identified by GC-MS, and the data were compared to those
of the authentic samples purchased from commercial sources.
After the completion of reaction, the organic layer was
separated from the aqueous layer. It was then washed with
3 × 25 mL water, separated, and finally dried over
magnesium sulfate. The anhydrous ethylenedichloride layer
thus obtained was distilled to remove solvent. The residue
was then crystallized in ethanol to obtain 1.41 g (81 mol %)
of 4-chloro-2-nitrophenol. The observed mp was 86.5 °C
which was in good agreement with the literature (mp 85-
87 °C). |