1,2-Diiodoethane → tert-Butyl N-[7-iodo-2-methylthiopyrazolo[1,5-a]pyridin-3-yl]carbamate

Participants

Reaction Steps

To a solution of tert-butyl N-[2-methylthiopyrazolo[1,5-a]pyridin-3-yl]carbamate (21.6 g) dissolved in tetrahydrofuran (1 L) was n-butyllithium (1.6M hexane solution; 130 mL) dropwise at −78° C. under a nitrogen stream, and the reaction mixture was stirred for 30 minutes. A solution of 1,2-diiodoethane (24 g) in tetrahydrofuran (50 mL) was added to the obtained reaction mixture, and stirring was continued for 1 hour. After adding saturated aqueous ammonium chloride to the reaction mixture, the temperature was raised to room temperature, extraction was performed with ethyl acetate and the organic extract was washed with water and brine. The obtained organic extract was dried over anhydrous magnesium sulfate and filtered, the solvent was evaporated under reduced pressure, the residue was purified by silica gel column chromatography and the title compound (21.5 g) was obtained as yellow crystals from the n-hexane:ethyl acetate (5:1) fraction.

Provenance & Evidence