Methanesulfonyl chloride → 4-Chloro-9-(2-trimethylsilanyl-ethoxymethyl)-9H-dipyrido[2,3-b;4',3'-d]pyrrole-6-carbonitrile-7-oxide

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Reaction Steps

A mixture of 9-(2-trimethylsilanylethoxymethyl)-9H-dipyrido[2,3-b;4′,3′-d]pyrrole-6-carbonitrile-1,7-dioxide (2.1 g, 5.9 mmol) in N,N-dimethylformamide (50 mL) was treated with methanesulfonyl chloride (0.78 mL, 10.0 mmol), and the reaction mixture was stirred at room temperature for 7 h. The reaction mixture was then diluted with ethyl acetate (150 mL) and water (200 mL). The layers were separated and the organic layer was dried over sodium sulfate, filtered, concentrated in vacuo, and purified by flash chromatography (silica, 40 g, ISCO, 5-85% ethyl acetate in heptane) to afford the title compound as a 6.5:1 mixture with 2-chloro-9-(2-trimethylsilanylethoxymethyl)-9H-dipyrido[2,3-b;4′,3′-d]pyrrole-6-carbonitrile-7-oxide respectively as an off-white solid (1.7 g, 77%). The mixture was used in the next step without any further purification. 1H NMR (CDCl3, 400 MHz): 8.86 (s, 1H), 8.39 (d, J=6.4 Hz, 1H), 8.27 (s, 1H), 7.94 (d, J=8.1 Hz, 1H), 7.32 (dd, J=7.9 Hz, 6.5 Hz, 1H), 6.55 (s, 2H), 3.73 (t, J=8.0 Hz, 2H), 0.93 (t, J=8.0 Hz, 2H), −0.04 (s, 9H).

Provenance & Evidence