Dimethylformamide → 7-phenylethynyl-5-(toluene-4-sulfonyl)-2-(3,4,5-trimethoxy-phenyl)-5H-pyrrolo[2,3-b]pyrazine

Participants

Reaction Conditions

Reaction Steps

7-Iodo-5-(toluene-4-sulfonyl)-2-(3,4,5-trimethoxy-phenyl)-5H-pyrrolo[2,3-b]pyrazine (275 mg, 0.49 mmol), PdCl2(PPh3)2 (17 mg, 0.02 mmol), and cuprous iodide (5 mg, 0.02 mmol) were placed in a 5 ml microwave vial. The vial was capped and purged with nitrogen. Triethylamine (0.35 ml, 2.45 mmol) and 2.5 ml of DMF were added through the septum and the flask was purged again with nitrogen three times. Ethynyl-benzene (0.19 ml, 1.75 mmol) was added and the reaction was heated in a microwave reactor at 100° C. for 30 minutes. The crude reaction mixture was diluted with ethyl acetate, washed with water two times, dried and concentrated. The mixture was purified by flash chromatography using a gradient of 0% ethyl acetate in hexanes up to 30% to yield 195 mg of 7-phenylethynyl-5-(toluene-4-sulfonyl)-2-(3,4,5-trimethoxy-phenyl)-5H-pyrrolo[2,3-b]pyrazine. MS: (M+H)+=540.

Provenance & Evidence