4-Mercaptobenzoic acid

Thiosalicylic (2-mercaptobenzoic) acid [147-93-3] M 154.2, m 164-165 , pK 3.54, pKj 8.80. Crystd from hot EtOH (4mL/g), after adding hot distd water (8mL/g) and boiling with charcoal. The hot soln was filtered, cooled, the solid collected and dried in vacuo (P2O5). Cryst from AcOH and sublimes in vacuo. 

Pd(dba)2, dppb, Et2NH or 2-mercaptobenzoic acid. THE or EtOH, 15-120 min, 99-100% yield. " Allyl carbonates and allyl ethers are cleaved similarly. 

Pd2(dba)3/l,4-bis(diphenylphosphino)butane (DPPB) in the presence of 2-mercaptobenzoic acid <95TL1267>. The Af-allylindolines can be easily oxidized to the corresponding indoles at room temperature with o-chloranil. Additionally, Al-allylanilines were also found to undergo aromatic 3-aza-Cope rearrangements in the presence of Zeolite catalysts to give indoline derivatives as the major product <96TL5281>. 

Simple large scale syntheses of 4-hydroxythiocoumarin and 2-methylthiochromone from 2-mercaptobenzoic acid have been devised <00SC1193> and efficient syntheses of various simple and fused thiopyran-4-ones and 4-thiones have been achieved through the reaction of ethylene trithiocarbonate and dibenzoylacetylene (Scheme 58) <00JCS(P1)1467>. 

Chlorprothixene Chlorprothixene, 2-chloro-9[(l-dimethylamino)-3-propyliden]thioxan-thene (6.2.7), has been proposed to synthesize starting from 2-chlorothixantone (6.2.3). The initial 2-chlorothixantone (6.2.3) is prepared from 2-mercaptobenzoic acid, the reaction of... 

Zinc and cadmium complexes of the novel tripod ligand (145) have also been described.1087 The reaction of Hg(HL)2 (HL = 2-mercaptobenzoic acid, 146) with cadmium nitrate leads to the novel CdHgL species, in which the cadmium is bonded to the carboxylate oxygen atom, and the mercury to the thiolate sulfur.1088... 

As a structure proof, the compound was prepared by an alternate route 5-chloroanthranilic acid, prepared by the chlorination of anthranilic acid, according to J. Am. Chem.Soc. 68, 1303 (1946) was converted into 5-chloro-2-mercaptobenzoic acid by the method described in J. Org. Chem., 18, 1380 (1953), and the latter was condensed with benzene by means of sulfuric acid to yield 10-(2-chloro)thiaxanthenone, identical with that obtained by the first method. 

From 2-mercaptobenzoic Acid. The most widely used method of 1,3-benzo-TA synthesis is the reaction of 2-mercaptobenzoic acid with compounds containing a cyano group to afford various 2-substituted 1,3-benzo-TAs 56 [aryl and benzyl (57MI1), chloromethyl, and carboethoxymethyl (60MI1)]. Note that nitriles of aliphatic acids (acetonitrile and others) do not react in these conditions. The reaction of 2-mercaptobenzoic acid with... 

Benzo-TAs 63 were obtained from 2-mercaptobenzoic acid and functionally substituted nitriles (malonodinitrile, cyanoacetamide, cyanoaceto-anilide, etc.). In this case, however, the formation of by-product 65 takes place. The ratio of yields of products 63 and 65 depends on the conditions. Thus, in pyridine only 1,3-benzo-TAs 63 are formed, while in acetic acid the ratio of mono and bis products 63 and 65 is 3 1. The authors suggest that the initial intermediate 62 may give 1,3-benzo-TAs 63, whose reaction with another molecule of 2-mercaptobenzoic acid leads to bis product 65,... 

As a rule, the interaction of functionally substituted nitriles with 2-mercaptobenzoic acid takes place at the expense of the cyano group s... 

The first stable perchlorates of 1,3-benzo-TA were isolated as dioxane complexes 205 in a reaction between 2-mercaptobenzoic acid and nitriles in the presence of 70% HC104 and acetic anhydride. Heating these complexes in acetic acid affords salts 206, which may be transformed into benzo-TA 56. Protonation of 56 initially gives cations 206, whose IR spectra show that they exist in an NH form (there is a strong bond at 1700-1730 cm"1) (85KGS562) (Scheme 74). 

Hydrogenation of benzo-TA 254 by hydrogen in situ in Sn/HCl leads to the ring cleavage and the formation of 2-mercaptobenzoic acid and arylamides (60MI1) (Scheme 99). 

The triphenyltin derivatives of oxalic acid 70a312, 70b313, mercaptoacetic acid 71314 and 2-mercaptobenzoic acid 72315 were prepared by the reaction of triphenyltin hydroxide with the corresponding amine and acid in a 1 1 1 molar ratio. 

Mercaptoacetic Add 2-Mercaptobenzoic Acid Methane Methanol Methionine Methotrexate Methylene Blue A-Methyl Glycine 5-Methylindole Methyl Isocyanate Methylmalonic Add Methyl Methacrylate Methylmethane Sulfonate Methyl Thiocyanate A-Methyl Thiourea Methyl Urea Naphthalene Nicotinic Acid Ornithine Orotic Acid Oxalic Acid Oxindole Palmitic Acid Paraldehyde Pentobarbital Phenol... 

From the reactions of Me3Bi or Ph3Bi with mercaptoacetic, 2- or 3-mercap-topropionic and 2-mercaptobenzoic acids, compounds 12-17 are obtained as analytically pure samples in 43-77% yields. These compounds are insoluble... 

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