反应详情

This thiol (9.16 g) was dissolved in a solution of barium hydroxide octahydrate (12.62 g) in water (250 ml) and the solution filtered. To the stirred and ice-cooled solution was then added dropwise 30% aqueous hydrogen peroxide (14.0 ml). After allowing to warm to room-temperature the mixture was heated on the steam bath for one hour with stirring. The resultant solution was filtered hot and then allowed to cool whereupon the barium salt of the sulphonic acid crystallised from solution. To the suspension of the barium salt was added with stirring 1.0N aqueous sulphuric acid (40 ml) and the resultant mixture heated on the steam bath for 15 minutes and then allowed to cool. The precipitate of barium sulphate was filtered off and the filtrate concentration to dryness in vacuo and the residue treated with ethanol and reconcentrated to dryness. Trituration with ethanol, filtration and washing with acetone gave 6-(4-toluoyl)pyridine-2-sulphonic acid (8.93 g) as a yellow solid. M.p.>300°.

1. filtrationthe solution filtered
2. temperatureice-cooled solution
3. additionwas then added dropwise 30% aqueous hydrogen peroxide (14.0 ml)
4. temperatureto warm to room-temperature the mixture
5. temperaturewas heated on the steam bath for one hour
6. stirringwith stirring
7. filtrationThe resultant solution was filtered hot
8. temperatureto cool whereupon the barium salt of the sulphonic acid
9. customcrystallised from solution
10. additionTo the suspension of the barium salt
11. additionwas added
12. stirringwith stirring 1.0N aqueous sulphuric acid (40 ml)
13. temperaturethe resultant mixture heated on the steam bath for 15 minutes
14. temperatureto cool
15. filtrationThe precipitate of barium sulphate was filtered off
16. concentrationthe filtrate concentration to dryness in vacuo
17. additionthe residue treated with ethanol
18. filtrationTrituration with ethanol, filtration
19. washwashing with acetone