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AssigneeSumitomo Seika Chemicals Co., Ltd.
InventorsMichio Suzuki, Hiroyuki Hata, Masato Yoshikawa, Toshiyuki Ohe, Hirokazu Kagano, Hiroshi Goda, Masahito Nakano, Masaki Teramoto
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The present invention is directed to a method for producing dichlorophenylthioglycolic acid which comprises reacting monobromodichlorobenzene or trichlorobenzene with a thioglycolate in a ratio of 0.5 to 2.5 mols of the latter to 1 mol of the former in a polar solvent, and to a method for producing dichlorophenylthioglycolic acid comprising further reacting the reaction mixture obtained as above with a monohalogenoacetate. The method of the present invention is very useful industrially, advantageously producing dichlorophenylthioglycolic acid in high yield.
A method for producing dichlorophenylthioglycolic acid, which comprises reacting monobromodichlorobenzene or trichlorobenzene with a thioglycolate in a ratio of 0.5 to 2.5 mols of the latter to 1 mol of the former in a polar solvent at a reaction temperature of 50.degree. to 220.degree. C.
Dependencies are inferred from the claim text.
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No related US applications are recorded in the indexed filing history.
Preparation of thiols, sulfides, hydropolysulfides or polysulfides: of sulfides
Having the sulfur atoms of the thio groups bound to acyclic carbon atoms of the carbon skeleton: the carbon skeleton being acyclic and saturated
Acyclic or carbocyclic compounds
Term ended 20 Nov 2011 (estimated)
USPTO file history isn’t available for this patent, so only indexed dates are shown.
The present invention relates to a method for producing dichlorophenylthioglycolic acid.
Dichlorophenylthioglycolic acid is a compound which is useful as an intermediate for thioindigo pigments, chemicals for the electronic industry, pharmaceuticals and agricultural chemicals.
The conventional methods for producing dichlorophenylthioglycolic acid are as follows:
The present invention is hereinafter described in more detail by means of the following working examples and comparative example, but the invention is not limited by these examples.
To a 300 ml four-necked flask equipped with a stirrer, a thermometer and a condenser were charged 24.9 g (0.110 mol) of 1-bromo-2,5-dichlorobenzene, 13.19 g (0.143 mol) of thioglycolic acid, 12.06 g (0.286 mol) of 95% sodium hydroxide and 100 g of dimethylsulfoxide, followed by stirring at 120.degree. C. for 4 hours. Then, after distilling off the dimethylsulfoxide under reduced pressure, 100 g of water was added to the residue. After dissolving the residue therein at 100.degree. C., the solution was cooled for crystallization and filtered to yield sodium 2,5-dichlorophenylthioglycolate, which was then dissolved in 100 g of water with heating and acidized with concentrated hydrochloric acid, filtered and dried to yield 19.6 g of a light yellowish white powder of 2,5-dichlorophenylthioglycolic acid. The yield based on 1-bromo-2,5-dichlorobenzene was 75.1%.
To a 300 ml four-necked flask equipped with a stirrer, a thermometer and a condenser were charged 24.9 g (0.110 mol) of 1-bromo-2,5-dichlorobenzene, 13.19 g (0.143 mol) of thioglycolic acid, 12.06 g (0.286 mol) of 95% sodium hydroxide and 100 g of dimethylsulfoxide, followed by stirring at 120.degree. C. for 4 hours. After cooling until 100.degree. C., 2,5-dichlorothiophenol salt produced as the side product was treated with 5.13 g (0.044 mol) of sodium monochloroacetate at the same temperature for 1 hour. Then, after distilling off the dimethylsulfoxide under reduced pressure, 100 g of water was added to 54.5 g of the residue. After dissolving the residue therein at 100.degree. C., the solution was cooled for crystallization and filtered to yield sodium 2,5-dichlorophenylthioglycolate, which was then dissolved in 100 g of water with heating and acidized with concentrated hydrochloric acid, filtered and dried to yield 23.5 g of a light yellowish white powder of 2,5-dichlorophenylthioglycolic acid. The yield based on 1-bromo-2,5-dichlorobenzene was 90.0%.