With benzylmercaptan

It was found that much better yields are obtained if the vinylpyridine is first converted into the corresponding benzyl pyridylethyl sulfide (by reaction with benzylmercaptan), followed by pyrolysis of the latter over glass helices at high temperature with either nitrogen or hydrogen sulfide as carrier gas37 I Eq. (16)]. 

In order to ensure that the reactivity of cjj-1,2-dihydroxy-1,2-dihydroacronycine diesters towards nucleophilic agents was similar to that of acronycine and precocene epoxides, the diester was reacted with benzylmercaptan (2i) in acidic medium. The cis and trans adducts 7 and with the sulfur atom linked to the benzylic position of the pyranyl ring were obtained in almost quantitative yield under these conditions (58). 

Transesterification (thiol exchange by reaction of a dithioe-ster with a thiol). Thioglycolic acid-based dithioesters are poor RAFT agents. FFowever, they can serve as precursors to other RAFT agents as they undergo facile reaction with other thiols to provide new dithioesters. For example, reaction of dithioester 86 with benzylmercaptan provides benzyl dithiobenzoate (103) in high yield (Scheme 25). ... 

The Sucholeiki thioether linkage can be synthesized via a disulfide bond (NpSSMpact) and addition of benzylbromide 408 or alternatively via the chlorine derivative and following reaction with benzylmercaptan. Other syntheses start from thiols that are converted with electrophiles. 

The C-S bond in purine derivatives undergoes cleavage under mild conditions by nucleophilic agents such as benzylmercaptan or glutathione in dimethylformamide with a phosphate buffer of pH 6.5 (277). The salt (110) of dithiazolylsulfide heated at 190 C yields the A-4-thiazo-line-2-thione (112) and 2-chlorothiazole (111) (Scheme 56) (278-280). 

Benzylmercaptan reacts with diacetylenes 57 under base-catalyzed conditions in aregio- and stereoselective fashion to form diadducts Z,Z-l,4-di(benzylthio)buta-1,3-dienes (59). In this case, monoadducts 58 can be isolated (96T12677). The reaction with r-butylmercaptans gives good results for diacetylenes with aromatic substituents. 

Reaction between benzylmercaptans and haloacetic acids yield benzylmercaptoacetic acids (57) which, via their acid chlorides, undergo an intramolecular Friedel-Crafts cyclization to produce isothiochromanones as in Eq. (24).233-235 Attempts to cyclize 57 with sulfuric acid,... 

Fig. 8. Recording of t—E curves during the course of a reaction Reaction of S-ben-zyl-isothiuronium chloride with hydroxide and carbonate ions in carbonate buffer pH 9.7. Initial concentration of S-benzylisothiuronium chloride 4 x 10 4M. Anodic waves of benzylmercaptan formed were recorded after intervals given in the polarogram. Curves starting at — 1.0 V towards more positive potentials, S.C. E., 200 mV/absc., h = 70 cm, full scale sensitivity 2.2 p.A...

Dibenzylsulfide. Figure 13 shows the identified products of aerobic and anaerobic metabolism of dibenzylsulfide. Babienzien et al. (68) incubated this substrate with a mixed population of aerobic bacteria and detected several water-soluble organic products. However, only benzylmercaptoacetic acid was identified. Kohler et al. (49) incubated dibenzylsulfide with a selected strain of Desulfovibrio utilizing molecular hydrogen under anaerobic conditions where sulfate served as the terminal electron acceptor. Toluene and benzylmercaptan were identified as metabolites. In addition, 35S-sulfide was found in cultures incubated with 35S-dibenzylsulfide. 

B) Preparation of Benzylthiomethyl-6-Chloro-7-Sulfamyl-3,4-Dihydrobenzothiadiazine-1,1-Dioxide - A mixture of 3-(chloromethyl)-6-chloro-7-sulfamyl-3,4-dihydrobenzothiadiazine-l,1-dioxide (0.02 mol) and benzylmercaptan (0.024 mol) in 20 ml of 10% sodium hydroxide and 20 ml of dimethylformamide is stirred at room temperature for 6 hours. After heating for 10 minutes on a steam bath, the mixture is cooled and acidified with 6 N HCI. The product, after recrystallization from acetone, melts at 210°-211°C. 

An account has also been given of the reaction between benzylmercaptan and cis-benzene trioxide.With a-mercapto esters, p-substituted phenyloxiranes undergo normal opening, without being affected by the substituents on the benzene ring. Chalcone oxides react with mercaptan with accompanying C-C bond cleavage (Eq. 308). ... 

One problem of prime importance is the reliable determination of the number of residues of ,/3-unsaturated amino acids in proteins. Direct amino acid analysis subsequent to total hydrolysis of proteins is not feasible. The ,/3-unsaturated amino acids are subject to degradation with the formation of amide (ammonia) and -keto-acid. The numbers and types of ,/3-unsaturated amino acids in nisin (1) and subtilin (10) and in the fragments of the two peptides were, nevertheless, determined by amino acid analysis, only, however, after the addition of mercaptan across the double bonds of dehydroalanine and dehydrobutyrine (19). Using benzylmercaptan, the addition products are S-benzylcysteine (from dehydroalanine) and /3-methyl-S-benzylcysteine (from dehydrobutyrine). The two thioether amino acids are eluted from ion exchange columns of the amino acid analyzer free from interference by other amino acids... 

Little information is obtained on sulfides or disulfides in the IR region. The compound carbon disulfide, S=C=S, is a thiocarbonyl, but atypical. It shows an intense band at about 1500 cm as seen in Fig. 4.54, but the rest of the IR region is clear, making CS2 a useful IR solvent. Figure 4.55 is the spectrum of benzylmercaptan and shows the SH stretch between 2500 and 2600 cm , along with the expected aromatic ring peaks and the characteristic monosubstituted benzene pattern between 1600 and 2000 cm . While the SH stretch is weak in the IR spectrum, it is strong in the Raman... 

Kuroda et r//.reported a cyclodextrin-sandwiched poiphyrin 109. The Fe(III) complex of this poiphyrin binds benzylmercaptan in an aqueou.s buffer solution at pH 7.0. Two molecules of benzylmercaptan were bound consecutively, with the first a.s.sociation constant larger than 10 M and the second association constant being 7 X lO M "The host also binds adamantanecarboxylate. a typical guest for cyclodextrin, with a binding constant of 7 X 10 M-. ... 

Experiments with labeled benzylmercaptane, however, showed no incorporation of radioactivity. Also, racemization appears to be faster than deuterium exchange at the a-carbon atom. Thus racemization via jS-elimination might occur only at elevated temperature, while other mechanism(s) could be opera-... 

Natural cinchona alkaloids were reported to promote the sulfa-Michael addition to different electron-poor alkenes as well. Catalysts 1 and 2 were employed by Pracejus et al. [11] in the moderately enantioselective additions (up to 54% ee) of benzylmercaptan to a-phthalimidomethacrylate. The same bases were found to promote the asymmetric addition of benzylmercaptan and tritylmercaptan to nitro-alkenes. Similar results were later reported with thioglycolic acid as the nucleophile [12]. Low enantioselectivities were obtained in the process catalyzed by different alkaloids such as bmcine, strychnine, and A-methyl ephedrine [11]. Catalyst 4 was successfully employed in the sulfa-Michael addition of thiophenol to maleic acid... 

Cyanide addition to the lactamic carbonyl group has been described in a reaction in which the cyanide ion acts as a catalyst (Fig. 14).The intermediate acyl cyanide can be attacked by an added nucleophile (allylic, propargylic, benzylic alcohols, aniline, benzylmercaptan). Comparative experiments were carried out using more classical procedures, such as under catalysis by potassium cyanide with stirring at room temperature, and with sodium alkoxides at -78 C. This last method provides the highest yields, up to 95% in most of the cases tested, but the sonochemical method proceeds under less basic conditions. Both methods preserve the integrity of the asymmetric center. 

For example, Meerwein Reaction of 78 followed by displacement of the resultant chloride with the sodium salt of benzylmercaptan provides 79. Conversion of the ester to the amide followed by oxidative chlorination/amination yields the sulfonamide 81. 

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