(4-Methanesulfonamidophenyl)boronic acid → 1,1-Dimethylethyl 2-{4-[(methylsulfonyl)amino]phenyl}-4,5,7,8-tetrahydropyrazolo[3,4-d]azepine-6(2H)-carboxylate

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Reaction Steps

To {4-[(methylsulfonyl)amino]phenyl}boronic acid (commercially available from e.g. Combi-Blocks) (127 mg, 0.29 mmol) in dichloromethane (3 ml) was added copper(II) acetate (107 mg, 0.59 mmol) and 4 Å molecular sieves (190 mg), and the reaction stirred at room temperature, open to air, for 10 minutes. 1,1-Dimethylethyl 4,5,7,8-tetrahydropyrazolo[3,4-d]azepine-6(2H)-carboxylate (may be prepared as described in Description 9) (70 mg, 0.29 mmol) was added and the reaction stirred at room temperature, open to air, overnight. The reaction mixture was diluted with methanol and filtered through a celite pad, washing with methanol. Solvent was evaporated in vacuo. Ethyl acetate and water were added, and the product was extracted into ethyl acetate (×3), washed with water (×1), then saturated sodium bicarbonate solution (×1), and then dried over magnesium sulfate. Solvent was evaporated in vacuo. The resulting crude product was purified by column chromatography on silica gel, eluting with a mixture of ethyl acetate in hexane (0-50%). Relevant fractions were combined and solvent evaporated in vacuo. The resulting crude product was purified further by Mass Directed Autopreparation to afford the title compound (D39). MS (ES+) m/e 407 [M+H]+.

Provenance & Evidence