4-(Tributylstannyl)pyridazine → methyl 1-isopropyl-3-methyl-6-(pyridazin-4-yl)-1H-indole-4-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a 50 ml round bottom flask was added; methyl 6-bromo-1-isopropyl-3-methyl-1H-indole-4-carboxylate (150 mg, 0.484 mmol), PdCl2(dppf)-CH2Cl2 adduct (39.5 mg, 0.048 mmol) and 1,4-Dioxane (4836 μl) followed with 4-(tributylstannyl)pyridazine (179 mg, 0.484 mmol) and a magnetic stir bar. The flask was equipped with a reflux condenser and an exhaust bubbler and heated to 105° C. The reaction solution changed to a dark brown at 30 minutes. LCMS (105 C—3 h) showed the reaction to be complete. The reaction solvent was removed in-vacuo and the remaining residue taken up with DMSO. (1.5 ml). The DMSO solution was purified by reverse phase HPLC using a Phenomenex Gemini 100×30 mm column, neutral acetonitrile and 0.1% formic acid in water, 40-70%, 10 min gradient. The desired fractions were dried in a Genovac EZ-2 evaporator and the solid residues combined. The product, methyl 1-isopropyl-3-methyl-6-(pyridazin-4-yl)-1H-indole-4-carboxylate, was obtained as a white solid. 1H NMR (400 MHz, METHANOL-δ4) 9.68 (δ, J=1.26 Hz, 1H), 9.19 (d, J=5.56 Hz, 1H), 8.20 (d, J=1.52 Hz, 1H), 8.13 (dd, J=2.53, 5.56 Hz, 1H), 7.98 (d, J=1.52 Hz, 1H), 7.48 (s, 1H), 4.96 (dt, J=6.60, 13.33 Hz, 1H), 4.00 (s, 3H), 2.39 (s, 3H), 1.56 (d, 6H). MS(ES) [M+H]+ 310.2.

Provenance & Evidence