4-Toluenesulfonyl chloride → 6-(2-Chloro-5-methoxy-1-methyl-1H-indol-3-yl)-5H-pyrrolo[2,3-b]pyrazine

Participants

Reaction Steps

A solution of 6-(5-methoxy-1-methyl-1H-indol-3-yl)-5H-pyrrolo[2,3-b]pyrazine [100 mg, Example 1(a)] in dimethoxy ethanol (25 mL), cooled to −78° C., was treated with a solution of n-butyllithium in hexanes (172 μl, 2.5M). After stirring for 30 minutes the mixture was treated with 4-toluenesulfonyl chloride (82 mg) then allowed to warm slowly to ambient temperature and then evaporated. The residue was subjected to flash chromatography on silica eluting with a mixture of dichloromethane and methanol (19:1, v/v) to give the title compound (45 mg) as a black solid. MS: 313 (MH+). 1H NMR [(CD3)2SO]: δ 12.20 (1H, s); 8.39 (1H, d, J=3 Hz); 8.21 (1H, d, J=3 Hz); 7.54 (1H, d, J=9 Hz); 7.30 (1H, d, J=2 Hz); 6.96 (1H, dd, J=9 and 2 Hz); 6.84 (1H, d, J=2 Hz); 3.82 (3H, s); 3.81 (3H, s).

Provenance & Evidence