Triethylamine → (S)-1-(2-azido-propyl)-7-fluoro-1,4-dihydro-indeno[1,2-b]pyrrole

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Reaction Steps

1.17 ml of methanesulfonyl chloride were added dropwise while stirring to a solution, cooled to 0°, of 1.73 g of (R)-1-(7-fluoro-1,4-dihydro-indeno[1,2-b]pyrrol-1-yl)-propan-2-ol and 4.2 ml of triethyl-amine in 60 ml of dichloromethane and the mixture was stirred at this temperature for an additional 1.5 hours. The reaction mixture was subsequently diluted with 150 ml of diethyl ether, washed twice with 60 ml of saturated sodium hydrogen carbonate solution each time and the combined aqueous phases were extracted once with 70 ml of diethyl ether. The combined organic phases were washed with 70 ml of saturated sodium chloride solution, dried over magnesium sulfate and evaporated in a vacuum. The brown oil obtained was dissolved in 50 ml of anhydrous dimethylformamide, treated with 973 mg of sodium azide and the reaction mixture was heated to 50° for 15 hours while stirring. After cooling, the solution was poured into 110 ml of water and extracted twice with 110 ml of diethyl ether each time and once with 60 ml of ethyl acetate. The combined organic phases were washed once with 80 ml of water and once with 80 ml of saturated sodium chloride solution, dried over magnesium sulfate and the solution was concentrated in a vacuum. The brown oil obtained was purified by column chromatography on silica gel (toluene). 750 mg (39%) of (S)-1-(2-azido-propyl)-7-fluoro-1,4-dihydro-indeno[1,2-b]pyrrole were obtained as a colorless oil.

Provenance & Evidence