Sodium borohydride → Fexofenadine

Participants

Reaction Steps

A mixture of 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-oxobutyl]-α,α-dimethylphenylacetic acid, prepared in accordance with Example 12, and 300 mg of NaBH4 in 25 mL of CH3OH was stirred overnight at room temperature. The mixture was then concentrated in vacuo. The residue was partitioned between EtOAc and H2O. The aqueous portion was treated with concentrated HCl until pH 6, then extracted with EtOAc. The organics were concentrated in vacuo. The residue was dissolved in EtOAc, filtered, and concentrated in vacuo to an oil. The oil was dissolved in CH3OH and concentrated to a solid. The solid was slurried with EtOAc, filtered, and rinsed with EtOAc to afford 4-[4-[4-(hydroxydiphenylmethyl)-1-piperidinyl]-1-hydroxybutyl]-α,α-dimethylphenylacetic acid.

Provenance & Evidence