To a flask containing (+/−)-2-[3-(2-methyl-piperidin-1-yl)-prop-1-ynyl]-5-(2-trimethylsilanyl-ethoxymethyl)-5H-pyrrolo[2,3-b]pyrazine (185 mg, 0.48 mmol) was added copper iodide (37 mg, 0.19 mmol), and DBU (0.34 mL, 2.28 mmol) in dry dimethyl acetamide (1 mL). The mixture was vacuum degassed and heated to 130° C. and stirred for 3 hours. The mixture was cooled to ambient and quenched via the addition of water (30 ml) and ethyl acetate (30 ml).The material was shaken in a reparatory funnel, and the ethyl acetate phase was collected. The aqueous phases were back extracted with ethyl acetate (2×25 ml), the organics combined, dried (MgSO4), filtered and stripped. The remainder was purified by preparative TLC using 25% ethyl acetate in hexanes as eluant. The product band was collected to provide 36 mg of (+/−)-8-(2-methyl-piperidin-1-yl)-3-(2-trimethylsilanyl-ethoxymethyl)-3H-3,4,8a-triaza-as-indacene as a brown-black oil. Note that starting material (90 mg) was also recovered. This material was subjected to the identical reaction conditions as above (but over-night heating), to provide an extra 12 mg of product. MS (M+H)+=385.
