N-((1,1-dimethylethoxy)carbonyl)-beta-alanine → (3-{4-[2,6-bis-(4-cyano-phenoxy)pyridine-3-carbonyl]piperazin-1-yl}-3-oxo propyl)carbamic Acid Tert-butyl Ester

Participants

Reaction Steps

A solution of 3-tert-butoxycarbonylamino-propionic acid, 0.177 g (0.94 mmol), in 3 ml of DMF was added dropwise to a stirred suspension of 0.72 g (3.76 mmol) of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) and hydroxybenzotriazole (HOBT) 0.508 g (3.76 mmol) in 5 ml of DMF at RT. That was followed by the addition of N,N-diisopropylethylamine (DIPEA) 0.242 g (1.88 mmol) while the temperature was maintained below 5. The mixture was stirred for 10 min and a solution of 4-[2,6-Bis-(4-cyano phenoxy)pyridine-3-carbonyl]piperazine (0.4 g, 0.94 mmol) in DMF (10 ml) was added followed by stirring overnight at RT. The reaction mixture was concentrated under reduced pressure and partitioned between water (150 ml) and ethyl acetate (150 ml) after the pH was adjusted to 2-3 with 6 N HCl. The organic phase was washed with 1 M Na2CO3 and saturated brine solution, dried over sodium sulphate and concentrated. The crude oily residue was purified by column chromatography using hexane-ethyl acetate (10:2) to afford 0.45 g of the required product. Percentage purity (LCMS): 10.3%. (M+1)=596.2 (with BOC).

Provenance & Evidence