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. 30, 1991
Filed:
Mar. 07, 1989
Masanobu Terao, Hyogo, JP;
Yuzo Maegawa, Osaka, JP;
Yasuyoshi Ueda, Osaka, JP;
Kiyoyasu Hashimoto, Nara, JP;
Takashi Omura, Hyogo, JP;
Daiei Chemical Co., Ltd., Hyogo, JP;
Sumitomo Chemical Co., Ltd., Osaka, JP;
Abstract
2,4-Dichloro-3-alkyl-6-nitrophenol, which is a precursor of 2,4-dichloro-3-alkyl-6-aminophenol useful for the production of a cyan coupler to be used with a sensitive material in the field of a photography in color, is industrially advantageously produced by (a) nitration of 2,4,5-trichloro-3-alkylbenzene, followed by hydrolysis of the resulting 2,4,5-trichloro-3-alkyl-6-nitrobenzene, or (b) hydrolysis of 2,4,5-trichloro-3-alkylbenzene-6-sulfonic acid or a salt thereof, followed by nitration of the resulting 2,4-dichloro-3-alkylphenol-6-sulfonic acid or a salt thereof, the starting material usable for these processes being 4-alkylbenzenesulfonic acid or a salt thereof, which is easily available.