反应详情

温度

110 °C

Disodium 2,3-dimethyl-3-(4-sulphonatobutyl)-3H-indole-5-sulphonate (5 g, 13.9 mmol) and sodium acetate (3.11 g) were stirred with methanol (100 ml) for 1 hour. Solvent removed by rotary evaporation and a further portion of methanol (100 ml) added. This was removed by rotary evaporation to yield an orange sticky solid. To this was added sulfolan (25 ml) and benzyl bromide (9.51 g, 55.6 mmol, 4 eq). The mixture was stirred overnight at 110° C. under a blanket of nitrogen. The cooled red solution was poured into stirring ethyl acetate (1 l) and the precipitate filtered off. The precipitate was washed with copious ethyl acetate and diethyl ether and then dried under vacuum. A sample was dissolved in water and analysed by reverse Phase TLC using acetonitrile modified with 0.1% TFA:water modified with 0.1% TFA (30:70). Separation yielded the product (Rf 0.6) and starting material (Rf 0.95). The product spot turned red on standing indicating quaternisation had taken place. Yield: 8 g.

1. customSolvent removed by rotary evaporation
2. additiona further portion of methanol (100 ml) added
3. customThis was removed by rotary evaporation
4. customto yield an orange sticky solid
5. additionThe cooled red solution was poured
6. filtrationthe precipitate filtered off
7. washThe precipitate was washed with copious ethyl acetate and diethyl ether
8. customdried under vacuum
9. dissolutionA sample was dissolved in water
10. customSeparation
11. customyielded the product (Rf 0.6)