Hexabutyldistannane → methyl2-(1-methyl-5-(methylsulfonyl)-1H-indazol-3-yl)-5-(pivaloyloxymethyl)-5H-pyrrolo[3,2-b]pyrazine-7-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a solution of 3-iodo-1-methyl-5-(methylsulfonyl)-1H-indazole (127 mg, 0.37 mmol), methyl 2-bromo-5-(pivaloyloxymethyl)-5H-pyrrolo[3,2-b]pyrazine-7-carboxylate (128 mg, 0.34 mmol) and Pd(PPh3)4 (20 mg, 0.017 mmol) in DMF (8 mL) was added hexa-N-butylditin (299 mg, 0.51 mmol). The reaction mixture was degassed by bubbling nitrogen for 3 minutes and refilled with nitrogen. The mixture was heated to 100° C. for 15 hours under nitrogen. After cooling to room temperature, water (40 mL) was added and product extracted with EtOAc (3×30 mL), organics combined dried with sodium sulfate, filtered and concentrated under reduced pressure. The residue was purified by column chromatography (silica gel, 200-300 mesh, eluting with EtOAc/petroleum ether=2:1) to give methyl2-(1-methyl-5-(methylsulfonyl)-1H-indazol-3-yl)-5-(pivaloyloxymethyl)-5H-pyrrolo[3,2-b]pyrazine-7-carboxylate (120 mg, 69.7%) as an off-white solid. LCMS: (M+H)+=500; 1H NMR (300 MHz, DMSO): δ 9.43 (d, 1H, J=1.2 Hz), 9.21 (s, 1H), 8.95 (d, 1H, J=1.2 Hz), 8.77 (s, 1H), 8.01 (s, 1H), 6.33 (s, 2H), 4.24 (s, 3H), 4.04 (s, 3H), 3.28 (s, 3H), 1.09 (s, 9H).

Provenance & Evidence