5-mercapto-, oxidation

Imidazole-5-carboxamide, 4-cyano-reduction, 5, 435 synthesis, 5, 461, 472 Imidazole-5-carboxamide, 4-mercapto-oxidation, 5, 445... 

Tertiary structure also refers to the overall shape of a molecule, especially to structures stabilized by disulfide bridges (cystine) formed by the oxidation of cysteine mercapto groups. 

Polyhydric alcohol mercaptoalkanoate esters are prepared by reaction of the appropriate alcohols and thioester using -toluenesulfonic acid catalyst under nitrogen and subsequent heating (16,17). Organotin mercapto esters are similarly produced by reaction of the esters with dibutyltin oxide (18). Pentaerythritol can be oxidized to 2,2-bis(hydroxymethyl)hydracryhc acid [2831-90-5] C H qO, ... 

A problem associated with the use of abrasive metal poHshes is that the fresh metal, which has been exposed by the cleaning, rapidly oxidizes or tarnishes. Thus, many modem poHshes contain inhibitors. Sulfur compounds, eg, alkyl benzyl thiols, commonly are used, as are mercapto esters such as lauryl thioglycolate [3746-39-2] and dialkyldisulfides (52—54). 

Hydrogen Sulfide andMercaptans. Hydrogen sulfide and propylene oxide react to produce l-mercapto-2-propanol and bis(2-hydroxypropyl) sulfide (69,70). Reaction of the epoxide with mercaptans yields 1-aLkylthio- or l-arylthio-2-propanol when basic catalysis is used (71). Acid catalysts produce a mixture of primary and secondary hydroxy products, but ia low yield (72). Suitable catalysts iaclude sodium hydroxide, sodium salts of the mercaptan, tetraaLkylammonium hydroxide, acidic 2eohtes, and sodium salts of an alkoxylated alcohol or mercaptan (26,69,70,73,74). 

The reactivity of halogens in pyridazine N- oxides towards nucleophilic substitution is in the order 5 > 3 > 6 > 4. This is supported by kinetic studies of the reaction between the corresponding chloropyridazine 1-oxides and piperidine. In general, the chlorine atoms in pyridazine A-oxides undergo replacement with alkoxy, aryloxy, piperidino, hydrazino, azido, hydroxylamino, mercapto, alkylmercapto, methylsulfonyl and other groups. 

Hydroxy and mercapto substituents at the 3- and 5-positions can also exist in tautomeric forms (see Section 4.01.5.2) and can be alkylated at either the substituent or the ring nitrogen atom. 3-Methoxy groups are not replaced by nucleophiles, but both 3- and 5-alkylthio groups react readily, as does 3-methoxy-l,2-benzisothiazole. Alkylthio compounds can be oxidized to sulfoxides and sulfones, and the latter readily undergo nucleophilic replacement. All the hydroxy compounds react with phosphorus pentachloride to give the chloro derivatives. 

Benzo[b]thiophene, 3-mercapto-2-methyl-synthesis, 4, 931 Benzo[6]thiophene, 2-methoxy-lithiation, 4, 773 synthesis, 4, 929 Benzo[6]thiophene, 3-methoxy-alkylation, 4, 765 synthesis, 4, 929 Benzo[6]thiophene, 4-methoxy-anodic oxidation, 4, 798 Benzo[6]thiophene, 5-methoxy-synthesis, 4, 929 Benzo[6]thiophene, 6-methoxy-synthesis, 4, 929 Benzo[6]thiophene, 7-methoxy-synthesis, 4, 929-930... 

Imidazole, 1 -hydroxy-2,4,5-triphenyl-3-oxides reactions, S, 455 Imidazole, iodo-nitrodehalogenation, 5, 396-397 Imidazole, 1-iodo-reactions, S, 454 stability, S, 110 Imidazole, 2-iodo-synthesis, S, 401 Imidazole, N-iodo-, S, 393 reactions, 5, 454 Imidazole, 4-iodo-5-methyl-iodination, 5, 400 Imidazole, 2-isopropyl-4-nitro-N-nitration, 5, 351 Imidazole, 2-lithio-reactions, S, 106, 448 Imidazole, 2-mercapto-l-methyl-as antithyroid drug, 1, 171 mass spectra, 5, 358 Imidazole, 1-methoxymethyl-acylation, S, 402 Imidazole, 5-methoxy-l-methyl-reactions... 

Imidazole-4-carbaldehyde, 5-mercapto-1 -phenyl-reactions, 5, 444 Imidazolecarbaldehydes oxidation, 5, 437 Imidazole-2-carbaldehydes condensation reactions, 5, 436 deacylation, 5, 93 decarbonylation, 5, 436 oximes, 5, 436 reactions, 5, 93... 

Indole, 3-hydroxymethyl-2-phenyl-stability, 4, 272 Indole, I-hydroxy-2-phenyl-synthesis, 4, 363 Indole, 2-iodo-synthesis, 4, 216 Indole, 3-iodo-reaetions, 4, 307 synthesis, 4, 216 Indole, 2-iodo-l-methyl-reaetions, 4, 307 Indole, 2-lithio-synthesis, 4, 308 Indole, 3-lithio-synthesis, 4, 308 Indole, 2-mereapto-tautomerism, 4, 38, 199 Indole, 3-mercapto-tautomerism, 4, 38, 199 Indole, 3-methoxy-synthesis, 4, 367 Indole, 5-methoxy-oxidation, 4, 248 Indole, 7-methoxy-2,3-dimethyl-aeetylation, 4, 219 benzoylation, 4, 219 Indole, 5-methoxy-l-methyl-reduetion, 4, 256 Indole, 5-methoxy-l-methyl-3-(2-dimethylaminoethyl)-reaetions... 

Selenophene, 2,5-dimethyl-3-mercapto-synthesis, 4, 956 tautomerism, 4, 946 Selenophene, 2,4-diphenyl-synthesis, 4, 135 Selenophene, 2,5-diphenyl-lithiation, 4, 949 UV spectra, 4, 941 Selenophene, 2-ethoxycarbonyl-mercuration, 4, 946 Selenophene, halo-reactions, 4, 955 Selenophene, 2-hydroxy-Michael reaction, 4, 953 tautomerism, 4, 36, 945, 953 Selenophene, 3-hydroxy-tautomerism, 4, 36, 945 Selenophene, 3-hydroxy-2,5-dimethyl-tautomerism, 4, 945, 953 Selenophene, 2-hydroxy-5-methyl-methylation, 4, 953 tautomerism, 4, 945 Selenophene, 2-hydroxy-5-methylthio-tautomerism, 4, 945 Selenophene, 3-iodo-synthesis, 4, 955 Selenophene, 3-lithio-reactions, 4, 79 synthesis, 4, 955 Selenophene, 2-mercapto-tautomerism, 4, 38 Selenophene, 3-mercapto-tautomerism, 4, 38 Selenophene, 2-mercapto-5-methyl-synthesis, 4, 956 tautomerism, 4, 946 Selenophene, 3-methoxy-lithiation, 4, 949, 955 synthesis, 4, 955 Selenophene, methyl-oxidation, 4, 951 synthesis, 4, 963 Selenophene, 2-methyl-lithiation, 4, 949 Selenophene, 3-methyl-synthesis, 4, 963... 

Thiazoline, trans-2-amino-4,5-dimethyl-synthesis, 6, 310 2-Thiazoline, 2-aryl-synthesis, 6, 307, 308, 309 2-Thiazoline, 2-arylamino-tautomerism, 6, 248 2-Thiazoline, 2-dialkylamino-synthesis, 6, 308 2-liiiazoline, 5-imino-synthesis, 5, 461 2-"niiazoline, 2-mercapto-hydrolysis, 6, 272 oxidation, 6, 272 synthesis, 6, 307 2-Thiazoline, 2-methyl-aldehyde synthesis from, 1, 469 2-Thiazoline, 2-methyl-acetylation, 6, 270 acylation, 6, 270 H NMR, 6, 243... 

Triazine-3,5-dione, 6-mercapto-metal complexes, 3, 456 oxidation, 3, 411... 

The use of an acidic solution of p-anisaldehyde in ethanol to detect aldehyde functionalities on polystyrene polymer supports has been reported (beads are treated with a freshly made solution of p-anisaldehyde (2.55 mL), ethanol (88 mL), sulfuric acid (9 mL), acetic acid (1 mL) and heated at 110°C for 4 min). The colour of the beads depends on the percentage of CHO content such that at 0% of CHO groups, the beads are colourless, -50% CHO content, the beads appear red and at 98% CHO the beads appear burgundy [Vdzquez and Albericio Tetrahedron Lett 42 6691 200]]. A different approach utilises 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (Purpald) as the visualizing agent for CHO groups. Resins containing aldehyde functionalities turn dark brown to purple after a 5 min reaction followed by a 10 minute air oxidation [Coumoyer et al. J Comb Chem 4 120 2002]. 

Hoffman and Gronowitz - have applied this technique with marked success to the study of hydroxy-, amino-, and mercapto-thiophenes. Similarly, it has been shown that pyrid-4-one exists predominantly as such and that 4-hydroxypyridine 1-oxide is in equilibrium with comparable amounts of l-hydroxypyrid-4-one. - The method has also been used to investigate the structure of ions (see Section II,C, of article II by Katritzky and Lagowski). 

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