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:
Aug. 14, 2001
Filed:
Apr. 11, 2000
Hirotada Iida, Nakano-Ku, JP;
Seiju Tobishima, Yotsukaido, JP;
Naoki Sato, Chiba, JP;
Nobuhiro Yoneyama, Soka, JP;
Yuki Hotta, Edogawa-Ku, JP;
Toshio Itahana, Edogawa-Ku, JP;
Yuichi Hagiwara, Inba-Gun, JP;
Toyo Gosei Kogyo Co., Ltd., Chiba, JP;
Abstract
An effective method for producing 1,2-naphthoquinone-2-diazide-4-sulfonyl chloride at high yield, wherein formation of impurities is prevented. The method includes the following steps: 1,2-naphthoquinone-2-diazide is reacted with chlorosulfuric acid, to thereby produce a mixture of a sulfonated compound and a chlorosulfonated compound of the diazide; and to the mixture, at least one substance selected from among thionyl chloride and phosphorus pentachloride is added for further reaction, to thereby obtain 1,2-naphthoquinone-2-diazide-4-sulfonyl chloride.