(3S,6S)-3,6-diisobutyl-4-(4-phenoxybenzoyl)piperazin-2-one 、
(3S,6S)-6-cyclopentyl-3-isobutylpiperazin-2-one 、
5-(4-氟苯基)-1,2,4-噁二唑-3-羧酸 以to give the product 294 (30.5 mg, 15.3% yield) as colorless oil的产率得到(3S,6S)-6-cyclopentyl-4-(5-(4-fluorophenyl)-1,2,4-oxadiazole-3-carbonyl)-3-isobutylpiperazin-2-one