Synthesis
General procedure for the synthesis of 5-methylthiophene-2-boronic acid from 2-methylthiophene and triethyl borate: 5-methylthiophene-2-boronic acid (4.42 g, 85% yield) was obtained by reacting 2-methylthiophene (3.6 g, 17.3 mmol) with n-butyllithium at -78 °C, followed by the addition of triethyl borate. Next, 5-methylthiophene-2-boronic acid (4.42 g) was reacted with methyl 5-bromo-2-iodobenzoate at 80 °C via Suzuki coupling reaction to synthesize intermediate 1 (7.78 g, 80% yield). Intermediate 1 was subsequently cyclized with CH3MgCl to give Intermediate 2 (3.14 g, 40% yield). Finally, intermediate 2 was reacted with 9-phenylanthracene boronic acid via Suzuki coupling to give compound 1 (3.3 g, 60% yield). The structure of compound 1 was confirmed by 1HNMR and mass spectrometry (MS).
