Sodium Carbonate → 4-(4-Bromo-3-methoxycarbonylmethyl-thiophen-2-yl)-benzoic acid

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Reaction Steps

Pd(PPh3)4 (0.046 g, 0.4 mmol was added to a degassed solution of methyl (2,4-dibromothien-3-yl)acetate (2.51 g, 8 mmol) and 4-carboxybenzeneboronic acid (1.32 g, 8 mmol) in Na2CO3(40 mL, 0.4 M, 16 mmol) and CH3CN (40 mL). The mixture was heated to reflux overnight under argon for 16 h. The solution was filtered hot and the filtrate was concentrated to about half volume. The solution was extracted with CH2Cl2. The aqueous phase was acidified with concentrated HCl and the resulting solid was collected by vacuum filtration and washed with H2O to yield 4-(4-bromo-3-methoxycarbonylmethyl-thiophen-2-yl)-benzoic acid (1.98 g) which was used without further purification.

Provenance & Evidence