反应详情

温度

-20 °C

After dissolving 2-hydroxy-4-methylbenzoic acid (24.54 g, 161.29 mmol) in methanol (300 ml), the solution was cooled to −20° C. A solution of bromine (26.03 g) in methanol (50 ml) was added dropwise over 1 hour. The reaction mixture was stirred at room temperature for 1 hour and then concentrated. The residue was heated to dissolution in methanol (100 ml) and water (40 ml) was added. The precipitated crystals were filtered off and washed with 50% methanol-water. The precipitated crystals in the filtrate were also filtered off and washed with 50% methanol-water. The crystals were combined and dried to yield the title compound (24.8 g) as white crystals.

1. concentrationconcentrated
2. temperatureThe residue was heated to dissolution in methanol (100 ml)
3. additionwater (40 ml) was added
4. filtrationThe precipitated crystals were filtered off
5. washwashed with 50% methanol-water
6. filtrationThe precipitated crystals in the filtrate were also filtered off
7. washwashed with 50% methanol-water
8. customdried