反应详情

5.0 g (0.03 mol) of 5-nitro-picolinic acid (Pharmazie 38 (1983), p. 593) and 4.87 g (0.03 mol) of carbonyidiimidazole were dissolved in 250 ml of THF and stirred at 60° for 3 hours. The mixture was subsequently treated with 5.75 g (0.03 mol) of 1-benzyl-4-hydroxy-piperidine, stirred at 0°-5° for 18 hrs., at room temperature for 3 hrs. and subsequently at 40° for 2 hrs. The reaction mixture was completely freed from solvent and the residue was chromatographed over neutral Alox (grade II) with dichloromethane as the eluent and recrystallized from ethyl acetate. 4.2 g (41%) of 1-benzyl-piperidin-4-yl 5-nitro-picolinate were obtained as yellow crystals; m.p. 175°-176°.

1. stirringstirred at 0°-5° for 18 hrs
2. wait, at room temperature for 3 hrs
3. waitand subsequently at 40° for 2 hrs
4. customthe residue was chromatographed over neutral Alox (grade II) with dichloromethane as the eluent
5. customrecrystallized from ethyl acetate