G. D. Searle and Co.
Patent: US5302601 A1, 1994 ;
US 5302601 A

Sawada, Yuki; Kayakiri, Hiroshi; Abe, Yoshito; Mizutani, Tsuyoshi; Inamura, Noriaki; Asano, Masayuki; Aramori, Ichiro; Hatori, Chie; Oku, Teruo; Tanaka, Hirokazu
Journal of Medicinal Chemistry, 2004 , vol. 47, # 10 p. 2667 - 2677

Uemura, Motokazu; Nishikawa, Naomi; Hayashi, Yuji
Tetrahedron Letters, 1980 , vol. 21, p. 2069 - 2072

Fujisawa Pharmaceutical Co., Ltd.
Patent: US6083961 A1, 2000 ;