5-(3,3-difluoroazetidin-1-yl)-6-(2-fluoroethoxy)pyridine-2-carboxylic acid 、
4,4-二氟-L-脯氨酰胺 盐酸盐 以to obtain the title compound (16 mg, 43%) as off-white solid, MS (ESI)的产率得到(2S)-1-[5-(3,3-difluoroazetidin-1-yl)-6-(2-fluoroethoxy)pyridine-2-carbonyl]-4,4-difluoropyrrolidine-2-carboxamide