Sodium Carbonate → 2-(3,4-Dimethoxy-phenyl)-imidazo[2,1-b][1,3,4]thiadiazole

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Reaction Conditions

Reaction Steps

A solution of 2-bromo-imidazo[2,1-b][1,3,4]thiadiazole (0.5 g, 2.5 mmol, 1 eq), 3,4-dimethoxyphenylboronic acid (0.683 g, 3.7 mmol, 1.5 eq), dioxane (12.5 mL) and Na2CO3 (2M aq. solution, 3.8 mL) was degassed for 20 minutes at room temperature. Pd(Ph3P)2Cl2 was added and the reaction heated at 110° C. for 2 h in an argon atmosphere. The reaction mixture was diluted with EtOAc and washed with water. The combined organic layers were dried (Na2SO4), filtered and concentrated, and the residue was purified by column chromatography (SiO2, cyclohexane/20-100% ethylacetate). The product was further purified by triturating with Et2O, filtered off and dried affording the desired product (0.080 g). 1H NMR (300 MHz, DMSO) δ/ppm 8.18 (d, J=1.4, 1H), 7.47 (m, 2H), 7.33 (d, J=1.4, 1H), 7.15 (d, J=8.3, 1H), 3.86 (s, 3H), 3.75 (s, 3H). The filtrate was concentrated, redissolved in DCM and purified by flash-chromatography (SiO2, DCM/1% MeOH) to afford the desired product (0.65 g, containing some Ph3PO) that was used as such in the next step.

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