Sodium Carbonate → 2-(2-Aminopyridin-3-yl)-1-benzothiophene-5-carboxylic acid

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Reaction Conditions

Reaction Steps

To the degassed mixture of 2-amino-3-iodpyridine (1.12 g, 5.09 mmol, 1 eq), 2-(dihydroxyboryl)-1-benzothiophene-5-carboxylic acid, [2-(dihydroxyboryl)-1-benzothiophene-5-carboxylic acid (1.3 g, 1.15 eq)], and aqueous sodium carbonate (2M, 7.6 mL, 3 eq) in dioxane (10 mL) was added Ph3P (267 mg, 0.2 eq) and Pd(OAc)2 (114.3 mg, 0.1 eq). The mixture was heated to 50° C. with vigorous stirring for 30 minutes. The yellow mixture was then partitioned between aq NH4Cl and MeOH—CHCl3 (1:5). Some solids precipitation was observed. After the pH was carefully adjusted to around 6, the whole mixture was filtered through a Buchner funnel to obtain a yellow solid. The solid was further triturated with MeOH/H2O to give 2-(2-aminopyridin-3-yl)-1-benzothiophene-5-carboxylic acid as a white-off solid in amount of 1.18 g after dried in vacuo (86%).

Provenance & Evidence