Method for purifying O, S-dimethyl N-acetylphosphoramidothioate

• US 5,684,174 A
• Filed: 09/26/1996
• Issued: 11/04/1997
• Est. Priority Date: 09/22/1994
• Status: Expired due to Fees

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Shirahata, Mamoru, Kiyoshima, Yujiro, Minamisaka, Kazuya, Sakito, Yoji, Iwata, Atukazu
• Primary Examiner(s): Richter, Johann
• Assistant Examiner(s): LUTZ, LAURA REBEKAH
• Application Number:
  US08/723,954
• Time in Patent Office: 404 Days
• Field of Search: 558/146, 558/178
• US Class Current: 558/146
• CPC Class Codes: C07F 9/025 Purification; Separation; Stabilisation; Desodorisation of organo-phosphorus compounds of natural phosphatides C07F9/103; phosphines C07F9/5095
• CPC Class Codes: C07F 9/2487 containing the structure P(=X)n-N-C(=X) (X = O, S, Se; n = 0, 1)

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.

Claims

1. A method for purifying O,S-dimethyl N-acetylphosphoramidothioate, which comprises 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.

2. A method according to claim 1, wherein the organic solvent is a C₁ -C₄ alkyl ester of C₁ -C₄ aliphatic carboxylic acid.

3. A method according to claim 2, wherein the ester of C₁ -C₄ aliphatic carboxylic acid is ethyl acetate.

4. A method according to claim 1, wherein the organic solvent is a (C₁ -C₄ alkyl) carbonate.

5. A method according to claim 4, wherein the organic solvent is methyl carbonate.

6. A method according to claim 1, wherein the organic solvent is a C₄ -C₈ aliphatic ketone.

7. A method according to claim 6, wherein the organic solvent is methyl ethyl ketone or methyl isobutyl ketone.