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. 01, 1997
Filed:
Sep. 21, 1995
Yoji Sakito, Oita, JP;
Mamoru Shirahata, Oita, JP;
Yujiro Kiyoshima, Oita, JP;
Kazuya Minamisaka, Oita, JP;
Atukazu Iwata, Takatuki, JP;
Sumitomo Chemical Company, Limited, Osaka, JP;
Abstract
A method for purifying O,S-dimethyl N-acetyphosphoramidothioate, which is characterized by subjecting a crude crystal of O,S-dimethyl N-acetylphosphoramidothioate to recrystallization by using a two-phase solvent system comprising water and an organic which is an aromatic hydrocarbon, an aliphatic carboxylic acid ester or aliphatic ketone, wherein the amount of water is 0.1 to 2 parts by weight and the amount of the organic solvent is 1 to 20 parts by weight to 1 part by weight of the crude O,S-dimethyl N-acetylphosphoramidothioate. A further method for purifying O,S-dimethyl N-acetylphosphoramidothioate, which is characterized by extracting O,S-dimethyl N-acetylphosphoramidothioate from an aqueous solution of crude O,S-dimethyl N-acetylphosphoramidothioate with an organic solvent which is a carbonate ester, an aliphatic carboxylic acid ester, an aliphatic ketone, an aliphatic alcohol or a mixture of two or more thereof, wherein the solubility of water in the organic solvent is in a range of from 1 to 20% by weight, and crystallizing O,S-dimethyl N-acetylphosphoramidothioate from the resulting organic phase.