- Process for preparing 2,5-dichlorophenylthioglycollic acid
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A valuable starting material for the manufacture of tetrachlorothioindigo pigments is 2,5-dichlorophenylthioglycollic acid which is prepared by: (a) diazotizing 2,5-dichloroaniline with aqueous alkali metal nitrite at acidic pH to produce 2,5-dichlorophenyl-diazonium salt, (b) reacting the 2,5-dichlorophenyl-diazonium salt from (a) with thiourea in an aqueous medium at acidic pH in the presence of a catalyst to produce 2,5-dichlorophenyl-isothiuronium salt of the formula STR1 wherein X? is an anion of a mineral acid, (c) hydroloyzing the 2,5-dichlorophenylisothiuronium salt from (b), without intermediate isolation, at alkaline pH to produce 2,5-dichlorothiophenol and (d) condensing the 2,5-dichlorothiophenol with monochloroacetic acid to produce 2,5-dichlorophenylthioglycollic acid.
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- HIGH-TEMPERATURE ORGANIC SYNTHESIS. XXVII. REACTIONS OF ALKANETHIONES WITH THE CHLORINE DERIVATIVES OF BENZENE, THIOPHENE, AND NAPHTHALENE
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Alkanethiols react effectively with chlorobenzene, its derivatives, 1-chloronaphthalene, and 2-chlorothiophene at 600-660 deg C with the preferential formation of the corresponding aromatic or heteroatomic thiols.Ethanethiol is most reactive.When it is used instead of hydrogen sulfide in reactions with chlorobenzene or its 4-substituted derivatives, the yield of the aromatic thiols, from which the phenylthiyl radicals are generated with greater difficulty, increases more sharply than the yield of the thiophenols, which generate the more stable 4-XC6H4S radicals.The side products of the reactions are the corresponding diaryl sulfides, thiophene, benzothiophene, and toluene.
- Voronkov, M. G.,Deryagina, E. N.,Sukhomazova, E. N.
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p. 755 - 760
(2007/10/02)
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- Process for the production of aryl thiols
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A process for the production of an aryl thiol, which comprises hydrogenating an aryl sulfochloride in a protic or aprotic solvent in the presence of platinum as catalyst, at a temperature between 100° and 180° C., with hydrogen under a pressure of 2 to 140 bar, in a single reaction step.
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- Cephalosporin displacement reaction
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The present invention is directed to a process for the displacement of the acetoxy group of a cephalosporanic acid by a sulfur nucleophile, in an organic solvent and under essentially anhydrous conditions.
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