The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 07, 2020
Filed:
May. 10, 2019
Sumitomo Dainippon Pharma Co., Ltd., Osaka, JP;
Toshikazu Yagi, Mie, JP;
Satoshi Suzuki, Tokyo, JP;
Hiroto Tatamidani, Osaka, JP;
Kazuki Hashimoto, Osaka, JP;
Sumitomo Dainippon Pharma Co., Ltd., Osaka, JP;
Abstract
The invention addresses the problem of providing a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione that is suited to industrial production. The invention provides a method for producing 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by reacting 3-bromo-3-buten-2-one and 2-hydroxy-1,4-naphthoquinone in the presence of a solvent, then obtaining crystals of 2-acetyl-4H,9H-naphtho[2,3-b]furan-4,9-dione by adding an alcohol-based solvent and/or water to the reaction system, and treating the crystals by using a specific adsorbent in the presence of a solvent.