3-Chloro-2-methylphenol

87-60-5

3260-87-5

1. In a 1000 mL three-necked flask equipped with a thermometer, a mechanical stirrer and a dropping funnel, 700 mL of 22% sulfuric acid solution was pre-filled and heated to 70 °C. 2. 8 g of 3-chloro-2-methylaniline was added to the above solution in batches, maintaining the temperature at 70 °C until completely dissolved. 3. The reaction mixture was heated to 90 °C and then cooled to 10-12 °C to form a suspension. 4. the diazotization reaction was carried out by slowly adding 88.4 g of 40% sodium nitrite solution dropwise under stirring, maintaining the temperature at 10-12 °C. 5. the resulting diazonium salt mixture was heated to 90 °C and then slowly added to a mixture containing 200 mL of methyl isobutyl ketone and 2 g of 96% sulfuric acid under vigorous stirring. 6. The reaction was held at 90 °C for about 15 minutes to complete, after which the emulsion was cooled to 70 °C for phase separation. 7. The organic phase was washed with 50 mL of water to remove inorganic impurities. 8. The selectivity of the thermal decomposition step was 99.1% (a/a) by gas chromatography (GC) analysis. 9. The organic phase was purified by distillation to give 66.9 g of 3-chloro-2-methylphenol with a GC purity of 99.2% (a/a). 10. The distillation residue was 2.3 g. The yield of the target product was calculated to be 93.1%.