Hydrochloric Acid → Methanesulfonic acid 5-[6-fluoro-1-(toluene-4-sulfonyl)-2,3-dihydro-1H-indol-5-yl]-pent-4-ynyl ester

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Reaction Steps

A solution of 50 mg (0.141 mmol) of 5-[6-Fluoro-1-(toluene-4-sulfonyl)-2,3-dihydro-1H-indol-5-yl]-pent-4-yn-1-ol and 0.072 ml (0.42 mmol) diisopropyl ethylamine in 2 ml CH2Cl2 was treated at 0° C. with 0.033 ml (0.42 mmol) methanesulfonylchloride and stirred at room temperature for one hour. Addition of aqueous 0.1M HCl, extraction with Et2O, drying of the organic layer with MgSO4, and evaporation of the solvent gave 60 mg of Methanesulfonic acid 5-[6-fluoro-1-(toluene-4-sulfonyl)-2,3-dihydro-1H-indol-5-yl]-pent-4-ynyl ester as brown oil of which 12 mg were dissolved in 0.5 ml DMF, treated with 0.043 ml (0.053 mmol) 2-(methylamino)ethanol and stirred at 80° C. during 2 hours. Evaporation of the solvent and excess 2-(methylamino)ethanol and chromatography on silica gel with EtOAc/MeOH/NEt3 10:1:0.1 gave 10 mg (82%) of 2-({5-[6-Fluoro-1-(toluene-4-sulfonyl)-2,3-dihydro-1H-indol-5-yl]-pent-4-ynyl}-methyl-amino)-ethanol as a light yellow oil, MS: 431 (MH+).

Provenance & Evidence