(3S,6S)-3,6-diisobutylpiperazin-2-one 、 5-(4-Cyclopropylphenyl)isoxazole-3-carboxylic acid 、
( 3S,6S)-3,6-diiso-butyl-4-((1R,2R)-2-phenylcyclopropanecarbonyl)piperazin-2-one 以to furnish 284 (120 mg, 85.9% yield) as a white solid的产率得到(3S,6S)-4-(5-(4-cyclopropylphenyl)isoxazole-3-carbonyl)-3,6-diisobutylpiperazin-2-one