Iodine → 2-iodo-1-tosyl-1H-pyrrolo[2,3-b]pyridine-4-carbonitrile

Participants

Reaction Steps

A stirred solution of diisopropylamine (0.38 mL) in tetrahydrofuran (7 mL), at −70° C. and under nitrogen, was treated with a solution of n-butyllithium in hexanes (1.06 mL, 2.5M) over 5 minutes, whilst maintaining the temperature below −65° C. After stirring for 20 minutes the mixture was added, at −70° C., to a solution of 1-(toluene-4-sulfonyl)-1H-pyrrolo[2,3-b]pyridine-4-carbonitrile (0.65 g, Reference Example 63) in tetrahydrofuran (15 mL) and stirred at −70° C. for 45 minutes. A solution of iodine (0.9 g) in tetrahydrofuran (10 mL) was then added at −70° C. The reaction mixture was allowed to warm up to room temperature over 1 hour, and stirred for 18 hours, then treated with water (10 mL). The reaction mixture was evaporated in vacuo and the residue partitioned between ethyl acetate (75 mL) and water (50 mL). The insoluble material was filtered, washed with ether and dried in vacuo to give the title compound (0.45 g) as a white solid. The filtrate was separated and the organics washed sequentially with saturated sodium thiosulphate solution (2×30 mL), water (30 mL) and brine (30 mL), dried over sodium sulphate and evaporated. The residue was triturated with diethyl ether to give the title compound (0.25 g) as a cream solid. TLC RF=0.43 (ethyl acetate/heptane 1:1). MS: 424 (MH+).

Provenance & Evidence