3-Bromo-4-fluorobenzoic acid → N-[(1S,2S,4R)-1-Benzyl-4-(3,3-dimethylbutylcarbamoyl)-2-hydroxypentyl]-3-bromo-4-fluorobenzamide

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Reaction Steps

N-Cyclohexylcarbodiimide-N′-methyl polystyrene (265 mg @ 1.70 mmol/g; ex. Novabiochem) was treated with a solution of 1-hydroxybenzotriazole (0.45 mmol) in DMF (1.0 ml) followed by 3-bromo-4-fluorobenzoic acid (99 mg, 0.45 mmol), dichloromethane (1 ml) and (2R,4S,5S)-5-amino-4-hydroxy-2-methyl-6-phenylhexanoic acid (3,3-dimethylbutyl)-amide (D2) (90 mg, 0.30 mmol) in dichloromethane (0.5 ml)/DMF (0.5 ml). After stirring gently overnight at room temperature, methylisocyanate polystyrene (150 mg @ 1.80 mmol/g; ex. Novabiochem) and tris-(2-aminoethyl)-amine polystyrene (250 mg @ 3.20 mmol/g; ex. Novabiochem) were added and the mixture was stirred for a further 1.5 h. It was then filtered and the spent resins were washed with DMF and dichloromethane. The combined filtrates were evaporated to dryness and the residue was filtered through a short column of silica gel to give the title compound, 126 mg.

Provenance & Evidence