4-{5-[(2-phenyl-5-trifluoromethyloxazole-4-carbonyl)amino]pyridin-2-yl}piperazine-1-carboxylic acid tert-butyl ester 、 2-((S)-3-{4-[(2-phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-phenylamino}-pyrrolidine-1-carbonyl)-cyclopentanecarboxylic acid 以to yield (1R,2R)-2-((S)-3-{4-[(2-phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-phenylamino}-pyrrolidine-1-carbonyl)-cyclopentanecarboxylic acid as a yellow oil的产率得到(1R,2R)-2-((S)-3-{4-[(2-phenyl-5-trifluoromethyl-oxazole-4-carbonyl)-amino]-phenylamino}-pyrrolidine-1-carbonyl)-cyclopentanecarboxylic acid