Diisopropylethylamine → (S)-tert-Butyl 3-methyl-2-(4-(4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)benzamido)butanoate

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Reaction Steps

To a solution of 4-(tetramethyl-1,3,2-dioxaborolan-2-yl)benzoic acid (2.0 g, 8.1 mmol) and (S)-tert-butyl 2-amino-3-methylbutanoate (2.0 g, 9.5 mmol) in DMF (10 mL) were added HATU (6.1 g, 16 mmol) and DIEA (4.2 g, 33 mmol). The reaction mixture was stirred at rt overnight. The reaction was then quenched with water (100 mL). The resulting mixture was extracted with DCM (2×100 mL), and the organic layer was concentrated under reduced pressure. The residue obtained was purified by flash column chromatography on silica gel (EtOAc/petroleum ether (1:50)) to obtain compound 43a as a white solid. Mass Spectrum (LCMS, ESI pos.): Calcd. for C22H34BNO5: 404.3 (M+H). Found 404.1.

Provenance & Evidence