Thiophenol 2,5-dichloro

Cationic-oxidative polymerization reactions have been developed to synthesize PPS under less severe conditions. For example, PPS has been obtained by a cationic-oxidative polymerization of thiophenol or diphenyl disulfide at room temperature. However, the resulting PPS has a low molecular weight due to premature precipitation. The cationic-oxidative polymerization reaction has been performed electrolytically [109] [Eq. (24)], with Lewis acids [110] [Eq. (25)], with 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) [111] [Eq. (26)], and with O2 in the presence of a catalytic amount of VO(acac)2 [112] [Eq. (27)]. 

Figure 3.28 Nucleophilic participation by carboxylate in the departure of various leaving groups from mixed acetals of phthalic hemialdehyde Rate enhancements of these spontaneous processes of 100 for 3,5-dichloro-phenolate departure, 22 for thiophenolate departure " and 20 for catechol monoanion departure were estimated from the rates of the p-phthalic derivatives intermolecular general acid catalysis of the catechol was also accelerated.

Regioselective displacement of chlorine from 4,5-dichloro-3(2//)-pyridazinones has been shown to be exceptionally dependent on the solvent and has been the subject of several studies. With 2-methyl and 2-phenyl-4,5-dichloro-3(2//)-pyridazinones as substrates, reaction with alkoxides occurs selectively at C-4 in less polar solvents (carbon tetrachloride, dioxane, THF, t-BuOH, pyridine), is nonselective in solvents of intermediate polarity (acetone, 2-propanol), and is selective for C-5 in polar solvents (EtOH, MeOH, DMF, DMSO) with the exception of acetonitrile, in which mixtures are obtained. Similar selectivity was seen with phenol and ethanethiol, but with thiophenol and ethyl... 

Aminobenzenethiols and their salts react with anthraquinones yielding nap-hthophenothiazines. A number of substituted e Jo-12,17-o-phenylene-12,17-dihy-dro-naphtho[2,3-u]-l,4-benzothiazino[3,2 -c]phenothiazines and substituted endo-i, 13-o-phenylene-8,13-dihydro-6-chloro-7H-naphtho[2,3-a]phenothiazin-7-ones have been synthesized (83PS(17)85, 82IJC(B)695) by the condensation of endo-9, 0-o-phenylene-2,3-dichloro-9,l0-dihydro-1,4-anthraquinone with substituted 2-amino-thiophenol and their zinc mercaptides, respectively. 

A soln. of thiophenol, ethyl bromide, Na2C03, and a little dichloro[bis(diphenylphos-phino)methane]platinum(II) in acetone boiled overnight ethyl phenyl sulfide. Y 75%. F.e. incl. 1,3-dithioethers, also mercaptals from 1,1-dihalides, s. P.C. Bulman Page et al.. Tetrahedron Letters 29, 4477-80 (1988). 

Ort/io-selectivity is generally observed in the reactions of 2,4-dichloro- and 2,4-difluoro-nitrobenzene with alkoxide and thiophenoxide ions [199]. Also in less activated systems, nucleophiles generated from phenols and thiophenols with potassium fluoride-alumina and 18-crown-6-polyether will react in DMSO with cyano- or nitro-substituted fluoro- or chloro-benzenes [200]. Interestingly, the reaction of difluorobenzenes with two diffoent alcohols can occur sequentially. Introduction of the first etho" function deactivates the ring, and use of more forcing conditions allows substitution of the second fluorine [201]. Consecutive displacements of fluorine and nitro groups have been observed in the reaction of ort/io-fluoronitrobenzene with chiral acyl bicyclic lactones in a highly enantioselective synthesis of spirooxindoles [202]. 

A high-temperature synthesis of thioxanthene from thiophenol and o-chloro-or o-bromo-toluene has been reported. Irradiation of the thiol esters (44 X = Cl, Br, I, or SOgMe Y = H) afforded the thioxanthone (45 Y = H) and p-tolyl disulphide. This rearrangement is believed to involve a 1,3-shift of the SCgHgMe group. When the dichloro-compound (44 X = Y = Cl) was irradiated, photosubstitution occurred, giving the sulphide (45 Y = p-Me-CgH4S) instead of the expected chloride (45 Y = Cl). The same product was... 

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