反应详情

温度

-5 °C

3-Amino-4-phenylthiobenzoic acid (110.27 g) is added to a heated solution of conc. sulfuric acid (81 ml) in water (400 ml), and the mixture is heated with stirring for 2 hours and then cooled to -5° C. with an ice-sodium chloride bath. To the mixture is added a solution of sodium nitrite (36.25 g) in water (80 ml) which is previously ice-cooled over a period of about one hour. The mixture is further stirred at 0°-5° C. for 30 minutes. To the mixture is added urea (2 g), and the mixture is stirred for 30 minutes to decompose the unreacted nitrous acid. The resulting mixture is gradually added with stirring to a mixture of conc. sulfuric acid (121 ml), anhydrous sodium sulfate (168 g) and water (112 ml) at 100°-110° C. over a period of one hour and 15 minutes. After the addition, the mixture is stirred at the same temperature for one hour. The reaction mixture is cooled, and the resulting brown granular precipitate is separated by filtration, washed with water, and dried at 50° C. overnight. The product is added to a mixture of methanol (1.4 liter) and conc. sulfuric acid (70 ml), and the mixture is refluxed with stirring for 2 hours. After the reaction is completed, the reaction mixture is concentrated under reduced pressure, and to the residue is added water (1.5 liter), and the mixture is extracted with ethyl acetate (500 ml×3). The combined extracts are dried over anhydrous sodium sulfate and concentrated under reduced pressure. The residue is extracted with heated hexane (4.2 liter), and the extract is cooled. The resulting yellow precipitate is separated by filtration to give methyl 3-hyroxy-4-phenylthiobenzoate (49.37 g).

1. temperaturethe mixture is heated
2. temperaturecooled over a period of about one hour
3. stirringThe mixture is further stirred at 0°-5° C. for 30 minutes
4. stirringthe mixture is stirred for 30 minutes
5. additionThe resulting mixture is gradually added
6. additionAfter the addition
7. stirringthe mixture is stirred at the same temperature for one hour
8. temperatureThe reaction mixture is cooled
9. customthe resulting brown granular precipitate is separated by filtration
10. washwashed with water
11. customdried at 50° C. overnight
12. additionThe product is added to a mixture of methanol (1.4 liter) and conc. sulfuric acid (70 ml)
13. temperaturethe mixture is refluxed
14. stirringwith stirring for 2 hours
15. concentrationthe reaction mixture is concentrated under reduced pressure
16. additionto the residue is added water (1.5 liter)
17. extractionthe mixture is extracted with ethyl acetate (500 ml×3)
18. dry with materialThe combined extracts are dried over anhydrous sodium sulfate
19. concentrationconcentrated under reduced pressure
20. extractionThe residue is extracted with heated hexane (4.2 liter)
21. temperaturethe extract is cooled
22. customThe resulting yellow precipitate is separated by filtration