IP Library Granted Patent US 4,831,265
Granted Patent Utility
US 4,831,265 · App. 07/033,864

Method of producing quinone derivatives

Inventors: Masazumi Watanabe, Isuke Imada
Patented Case View Patent ↗
Granted: May 16, 1989 Filed: Apr 3, 1987
Inventors
Masazumi Watanabe
Isuke Imada
Assignee (at issue)
Takeda Chemical Industries Ltd.

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Quick Facts
Patent No.
US 4,831,265
App. No.
07/033,864
Filed
1987-04-03
Granted
1989-05-16
Kind
A