发明名称 |
Process for synthesis of fipronil |
摘要 |
A process for preparation of Fipronil (i.e. 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyano-4-trifluoro-methylsulphinyl-pyrazole) is provided, which comprises oxidizing 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyano-4-tri-fluoromethylthio-pyrazole with sulfuric acid and hydrogen peroxide as oxidizing agent in the presence of a solvent such as ethylene dichloride, chlorobenzene.; |
申请公布号 |
US9029564(B2) |
申请公布日期 |
2015.05.12 |
申请号 |
US201114122721 |
申请日期 |
2011.12.15 |
申请人 |
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发明人 |
Gharda Keki Hormusji |
分类号 |
C07D231/44 |
主分类号 |
C07D231/44 |
代理机构 |
Whiteford, Taylor & Preston, LLP |
代理人 |
Whiteford, Taylor & Preston, LLP ;Stone Gregory M. |
主权项 |
1. A process for preparing fipronil, said process comprising the following steps:
a. oxidizing, in a solvent selected from the group consisting of ethylene dichloride, methylene dichloride, carbon tetrachloride, chloroform, dibromoethane, bromobenzene, chlorobenzene and ortho-dichlorobenzene, a reactant mixture containing a compound 5-amino-1-(2,6-dichloro-4-trifluoromethylphenyl)-3-cyano-4-trifluoro methyl thio-pyrazole of formula IIand concentrated sulfuric acid having concentration in the range of 75% to 98% w/w, with hydrogen peroxide having concentration in the range 40 to 70% w/w, at a temperature in the range of −10° C. to 40° C. to obtain an oxidized product mixture;
b. quenching said product mixture with water at a temperature in the range of 10 to 25° C.; c. heating the quenched product mixture at a temperature in the range of 60 to 70° C. to obtain a biphasic system containing an aqueous phase containing sulphuric acid and an organic phase containing the oxidized product; d. isolating said organic phase by separating the aqueous phase; e. neutralizing the isolated organic phase containing the oxidized product to obtain crude fipronil; and f. crystallizing the crude fipronil to obtain crystallized fipronil. |
地址 |
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