反应详情

The Boc-protecting group on 0.530 g, 1.41 mmol of the 2-(4-Fluorobenzenesulfonyl)-indole-1-carboxylic acid tert-butyl ester from Step 1 was removed by stirring at room temperature in 3 mL of neat TFA. The reaction mixture turned a light burgundy color while stirring. The TFA was removed by adding 25 mL of toluene and removing the solvent/TFA as an azeotrope. This was repeated and the oily residue was then transferred to a sealed tube using 5 mL of DMSO. Solid piperazine (0.61 g, 7.06 mmol, 5 eq.) was added, the tube was sealed, and the reaction mixture heated at 100° C. (bath temp.) for a period of 16 h. The reaction mixture was allowed to cool to room temperature, diluted with 400 mL of ethyl acetate, then washed sequentially with saturated NaHCO3 solution, water, brine, and dried over anhydrous magnesium sulfate. Evaporation of the solvent gave an amber glass which was treated with anhydrous diethyl ether. Hexane (25 mL) was added to the solution, causing a small amount of solid to precipitate out of solution. The mixture cooled was to 0° C. in an ice-water bath, followed by vacuum-filtration of the off-white solid. After drying, 0.150 g, 0.44 mmol, 31.1% yield of 2-(4-Piperazin-1-yl-benzenesulfonyl)-1H-indole was obtained, with a melting point range of 246–248.5° C. and M+H of 342.

1. customwas removed
2. stirringwhile stirring
3. customThe TFA was removed
4. additionby adding 25 mL of toluene
5. customremoving the solvent/TFA as an azeotrope
6. customthe oily residue was then transferred to a sealed tube
7. customthe tube was sealed
8. temperaturethe reaction mixture heated at 100° C. (bath temp.) for a period of 16 h
9. temperatureto cool to room temperature
10. washwashed sequentially with saturated NaHCO3 solution, water, brine
11. dry with materialdried over anhydrous magnesium sulfate
12. customEvaporation of the solvent
13. customgave an amber glass which
14. customto precipitate out of solution
15. temperatureThe mixture cooled
16. customwas to 0° C. in an ice-water bath
17. filtrationfollowed by vacuum-filtration of the off-white solid
18. customAfter drying