4-Iodobenzoic acid → 4-[Cyclopropyl-(4-iodo-benzoyl)-amino]-piperidine-1-carboxylic acid tert-butyl ester

Beteiligte Stoffe

Reaktionsschritte

2-(1H-Benzotriazol-1-yl)-1,1,3,3-tetramethyluronium tetrafluoroborate (2.67 g) is added to a solution of 4-iodo-benzoic acid (2.06 g) and ethyldiisopropylamine (2.88 mL) in N,N-dimethylformamide (15 mL) at room temperature. The solution is stirred for 10 min prior to the addition of 4-cyclopropylamino-piperidine-1-carboxylic acid tert-butyl ester (2.00 g). The resulting mixture stirred at room temperature overnight. The mixture is concentrated in vacuo and the residue is mixed with water and ethyl acetate. The organic phase is separated, washed with water and aqueous NaHCO3 solution, dried, and the solvent is evaporated. The crude product is used for the next reaction step without further purification. LC (method 5): tR=2.32 min; Mass spectrum (ESI+): m/z=471 [M+H]+.

Herkunft & Nachweise