4.6- Dimethyl-2-mercapto-5-

Pyridin 3-Cyan-4,6-dimethyl-2-mercapto- E16a, 765 (Pyridin-Ringschl.)... 

C11H16N305S+ Cl- 2,2 -Anhydro-(l-/ -D-arabinofuranosyl-5-dimethyl-mercapto-6-oxocytosine chloride) (AFMSCY)166 P212121 Z = 4 DX= 1.57 R = 0.042 for 1,117 intensities. The glycosyl disposition of the anhydronucleoside is constrained to the syn (—57.3°) orientation. The conformation of the D-arabinofuranosyl group is a flat-... 

CiiHi9N305S -C1 2,2 -Anhydro-(l-J -D-arabinofuranosyl-5-dimethyl-mercapto-6-oxocytosine chloride) (AFMSCY) ... 

Other sulfur compounds such as thiourea, ammonium dithiocarbamate, or hydrogen sulfide also lead to 2-mercaptothiazoles. Thus thiourea has been used in the syntheses of 4,5-dimethyl (369) and 4-aryl-2-mercapto-thiazoles (Table 11-30) (519). The reactions were carried out by condensing the ia -thiocyanatoketones with thiourea in alcohol and water acidified with hydrochloric acid. By this procedure, 4-aryl-2-mercaptothiazoles were obtained in yields of 40 to 80% with bis-(4-aryl-2-thiazolyl) sulfides as by-products (519). These latter products (194) have also been observed as a result of the action of thiourea on 2-chloro-4-arylthiazole under the same experimental conditions. They can be separated from 2-mercaptothiazoles because of their different degrees of solubility in sodium hydroxide solution at 5%. In this medium bis-(4-phenyl-2-thiazolyl)sulfide is... 

Furoxans, diethyl-synthesis, 6, 423 Furoxans, dihalo-synthesis, 6, 423 Furoxans, dimethyl-NMR, 6, 397 O NMR, 6, 398 Furoxans, diphenylring cleavage, 6, 404 synthesis, 6, 423 Furoxans, hydroxy-reactions, 6, 414 Furoxans, mercapto-reaotions, 6, 414 Furoxans, nitro-as explosives, 6, 426 reactions, 6, 413-414 reduction, 6, 423 Furoxans, phenyl-reactions... 

Indazole, 5,5-dimethyl-3-trifluoromethyl-4,5-dihydro-trichomonacidal activity, 5, 291 Indazole, 2-ethoxycarbonyl-reactions, 5, 269 Indazole, 3-fluoro-synthesis, S, 263 Indazole, 1-germyl-synthesis, 5, 236 Indazole, 1-glycosyl-synthesis, 5, 289 Indazole, 2-glycosyl-synthesis, 5, 289 Indazole, halo-reactions, S, 266 Indazole, 2-hydroxy-methylation, 5, 269 Indazole, 3-hydroxy-reactions, S, 264 Indazole, 6-hydroxy-diazo coupling, 5, 86 Indazole, hydroxyphenyl-synthesis, S, 288 Indazole, 3-iodo-synthesis, S, 241 Indazole, l-isopropyl-3-phenyl-reduction, 5, 243 Indazole, 3-mercapto-1 -substituted tautomerism, 5, 265 Indazole, methoxy-... 

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... 

The ratio, at equilibrium, of the hydrated to anhydrous forms (for both neutral species and anions) has been measured for the following 2-hydroxjrpteridine and its 4-, 6-, and 7-methyl and 6,7-dimethyl derivatives 6-hydroxypteridine and its 2-, 4-, and 7-methyl derivatives 2,6-dihydroxypteridine and 2-amino-4,6-dihydroxypteridine. The following showed no evidence of hydration 4- and 7-hydroxy-pteridine 2,4-, 2,7-, 4,7-, and 6,7-dihydroxypteridine and 2-amino-4-hydroxypteridine. The kinetics of the reversible hydration of 2-hydroxypteridine and its C-methyl derivatives (also 2-mercapto-pteridine) have been measured in the pH region 4-12, and all these reactions were found to be acid-base cataljrzed. The amount of the hydrated form in the anions is always smaller than in the neutral species, but it is not always negligible. Thus, the percentages in 2-hydroxy-, 2-hydroxy-6-methyl-, 2-mercapto-, and 2,6-dihydroxypteridine are 12, 9, 19, and 36%, respectively (see also Table VI in ref. 10). 

Kinetic studies have been carried out on the displacement reactions of various chloroazanaphthalenes with ethoxide ions and piperi-dine. - 2-Chloroquinoxaline is even more reactive than 2-chloro-quinazoline, thus demonstrating the powerfully electrophilic nature of the -carbon atoms in the quinoxaline nucleus. The ease of displacement of a-chlorine in the quinoxaline series is of preparative value thus, 2-alkoxy-, 2-amino-, - 2-raethylamino-, 2-dimethyl-amino-,2-benzylamino-, 2-mercapto-quinoxalines are all readily prepared from 2-chloroquinoxaline. The anions derived from substituted acetonitriles have also been used to displace chloride ion from 2-chloroquinoxaline, ... 

The supported aqueous phase methodology was applied to the system Pd(OAc)2/5 TPPTS, a catalytic precursor for the Trost-Tsuji reaction. The characterization of the solid by 31P MAS NMR confirms the presence of Pd°(TPPTS)3 as the main surface species. The catalytic properties of the solid were tested for the allylic substitution of E-cinnamylethylcarbonate by different nucleophiles such as ethyl acetoacetate, dimethyl malonate, morpholine, phenol, and 2-mercapto-pyridine. The absence of palladium leaching was demonstrated, and having solved the problem of water leaching from the solid to the organic phase, the SAP-Pd catalyst was successfully recycled several times without loss in its activity. It was used in a continuous flow experiment which... 

Mercapto-l,2,4-thiadiazoles exist as an equilibrium of tautomers with the equilibrium favoring the thione tautomer. They are acidic with a pA a of around 5. A variety of methylating agents (e.g., diazomethane, dimethyl sulfate and methyl iodide) give S-methylated products and no N-methylation has been observed. They are readily oxidized to sulfoxides and sulfones with either z-chloroperbenzoic acid or hydrogen peroxide in acetic acid <1996CHEC-II(4)307>. There have been no new publications on S-linked substituents since the publication of CHEC-II(1996). 

Glutamic acid and its salts (especially the sodium salt) enhance the flavour of many convenience foods. Bejaars et al. (1996) described the determination of free glutamic acid in soups, meat products and Chinese food. The method involves hot water extraction of test portions followed by filtration and dilution. The extracts were treated with N,N-dimethyl-2-mercapto-ethyl-ammonium chloride and o-phtaldialdehyde to convert glutamic acid into a stable fluorescent, l-alkylthio-2-alkyhsoindole. Homocysteic acid was used as the internal standard. Separation was made on a Ci8 column, eluted with... 

Dann and Dimmling showed that (2,5-dimethyl-3-thienylthio)acetic acid (86) may by cyclized to 4,6-dimethyl-2,3-dihydrothieno[3,4-6]-thiophen-3-one (87) by anhydrous hydrogen fluoride, and then reduced to 4,6-dimethylthieno[3,4-b]thiophene (88). The latter was obtained by cyclization of acetal (89) synthesized from 3-mercapto-2,S-c ethylthiophene (90) and bromoacetaldehyde dimethylacetd using hydrogen fluoride at 70°-80°. The synthetic route is illustrated by Scheme 6. 

Das 5,6-Diamino-indol I kondensiert mit Thiophosgen zu 5,5(7,7) -Dimethyl-2-mercapto-6-oxo-1,5,6,7-tetrahydro-(pyrrolo[2,3-f benzimidazoiy (19% Schmp. > 300°). Das analoge Umset-zungsprodukt mit Phosgen selbst diirfte entgegen der Formulierung in Lit.215 als cyclischer, nicht aromatischer Harnstoff vorliegen215. 

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