2-(Piperidin-4-yl)-1,3-benzothiazole → alpha-(R)-(3-(S)-((4-(benzothiazol-2-yl)piperidin-1-yl)methyl)-4-(S)-phenylpyrrolidin-1-yl)-cyclohexaneacetic acid, 4-methoxybenzyl ester

Participants

Reaction Steps

To a solution of 52 mg of α-(R)-(3-(R)-formyl-4-(S)-phenylpyrrolidin-1-yl)-cyclohexaneacetic acid, 4-methoxybenzyl ester (prepared above as Aldehyde 5) and 50 mg of 2-(piperidin-4-yl)benzothiazole (from Step B) in 2.5 mL of THF was added two spatula tips of 3 Å molecular sieves. After stirring at room temperature for 20 mim., 50 mg of sodium triacetoxyborohydride was added and the reaction was stirred at room temperature for 18 hours. The reaction was quenched with MeOH and diluted with EtOAc. After filtering molecular sieves, the filtrate was concentrated under reduced pressure. The residue was partitioned between EtOAc and water. The organic layer was washed with brine and dried over anhydrous MgSO4. Concentration under reduced pressure followed by flash chromatography eluting with 20% EtOAc in hexane followed by 50% EtOAc in hexane afforded 56 mg of the title compound as a white solid.

Provenance & Evidence