Methyl isobutyrate → 2-[6-[(4-tert-Butylphenyl)sulfonyl]-2-(trifluoromethyl)-6,11-dihydro-5H-pyrido[2,3-b][1,5]benzodiazepin-8-yl]-2-methylpropanoic acid methyl ester

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Reaction Steps

To methyl isobutyrate (128 mg, 1.25 mmol) in toluene (5 mL) was added 1.46 mL of LiHMDS (1.0 M in PhMe, 1.46 mmol) at 0° C. After stirring at rt for 10-15 min, the mixture was transferred via cannula to a mixture of intermediate 53 (225 mg, 0.416 mmol), Pd(dba)2 (24 mg, 0.042 mmol), and tri-t-butylphosphonium tetrafluoroborate (12 mg, 0.042 mmol). After stirring at rt for 48 hrs, the reaction was quenched with aqueous NH4Cl (20 mL) and the product was extracted with EtOAc (50 mL). The extracts were washed with water (30 mL) and brine (30 mL), dried over MgSO4, filtered, and concentrated in vacuo. The residue was purified on silica gel column eluting with 5-30% EtOAc in hexanes to afford the title compound. LCMS: m/e 562.2 (M+H)+.

Provenance & Evidence