Phosphorus oxychloride → 6-Methyl-N,N-dicyclopentylnicotinamide

Beteiligte Stoffe

Reaktionsschritte

To a suspension of 6-methylnicotinic acid (1.37 g, 10 mmol) in toluene (10 ml), N,N-dicyclopentylamine (1.84 g, 12 mmol) was added To the homogenous solution obtained, phosphorus oxychloride (0.23 mL, 12 mmol) was injected in dropwise fashion. The reaction mixture was then immersed in an oil-bath at 130° C. and refluxed for 8 h. The reaction flask was cooled and stirred at room temperature. After 16h, the reaction was quenched with water and extracted in ethyl acetate. The organic layer was successively washed with aq. potassium carbonate, water and brine. After drying (MgSO4), the solvent was removed. The crude product (2.5 g) was chromatographed (silica gel, ethyl acetate/acetonitrile 100/1.5) to give the title compound (1.2 g, 44%). IR (KBr)1625, 1590, 1450, 1430, 1375, 1340, 1290, 1130, 840, 750 cm-1 ; 1H NMR (CDCl3) 1.4-2.35 (m, 16H), 2.57 (s, 3H), 3.6-3.9 (m,2H), 7.17 (d, J=8 Hz, 1H), 7.6 (dd,J=3,8 Hz, 1H), and 8.5 ppm (d,J=3 Hz,1H).

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