2- Mercapto-2-thiazoline

A. 2-Allylthio-2-thiazoline [Thiazole, 4,5-dihydro-2-(2-propenyltliio)-]. A solution of 11.9 g. (0.100 mole) of 2-mercapto-2-thiazoline [2-Thiazoli-dinethione] (Note 1) in 00 ml. of tetrahydrofuran is prepared in a 200-ml., one-necked, round-bottomed flask fitted with a 25-ml.,... 

Figure 17-12. Biocides for hydraulic fracturing fluids 2-mercaptobenzoim-idazole, 2-mercaptobenzothiazole, 2-mercaptobenzoxazole, 2-mercapto-thiazoline, 2,5-dimercapto-1,3,4-thiadiazole, and 2-imidazolidinethion.

In 1995 Schwarz et al.159 described novel heterocyclic structures able to adsorb selectively immunoglobulins. The structures contained sulfur and nitrogen. Reported ligands were 2-mercapto-pyridine,2-mercapto-pyrimidine, and mercapto-thiazoline. These structures were chemically immobilized on silica and agarose beads using epoxy-activated matrices. Binding capacities for silica based material were about 25 mg of IgG per milliliter of resin, while for agarose beads it was about 18 mg/mL. 

R=H,alkyl) with aqueous NaOH and CS2 at reflux gave the 2-mercapto-thiazolines(113). In the former case lower temperatures allowed isolation of NaSC(=S)NHCHRCH20S02Na which could be thermally cyclised to (113). Similarly, 2-chloroalanine and CS2 form (113 R=C02H) in the presence of base [NHj,OH,Na0H,K2CO2 or... 

The nucleophUic reactivity in neutral medium has been used extensively to prepare various thioethers of thiazole (122). In acidic medium, alkylation may be performed with alcohols (123, 124). An unexpected reaction encountered was the decarboxylation of 2-mercapto-4-methyl-5-thiazolecarboxyhc acid (60) when treated with butyl alcohol under acidic conditions (Scheme 27) (123). Reaction between A-4-thiazoline-2-thione... 

A-2-Thiazoline-5-thiones are generally not obtained by direct heterocyclization reactions (352). Instead, most of the reported preparations involve reactions in which the thiazole ring is already formed with the suitable mercapto precursors in the 5-position. 

Many mercaptoazoles exist predominantly as thiones. This behavior is analogous to that of the corresponding hydroxyazoles (c/. Section 4.02.3.7). Thus oxazoline-, thiazoline- and imidazoline-2-thiones (521) all exist as such, as do compounds of type (522). However, again analogously to the corresponding hydroxyl derivatives, other mercaptoazoles exist as such. 5-Mercaptothiazoles and 5-mercapto-l,2,3-triazoles (523), for example, are true SH compounds. 

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... 

Thiazoline, 2-ethylthio [Thiazole, 2-(ethylthio)-4,5-dihydro-], 82 2 Thiazohne, 2-mercapto [2 Thiazohdine-thione], 77... 

Another class of new ligands was prepared in quantitative yields by Feringa et al., in 1997, by reaction between a-mercapto acids, aniline and 2-pyridine-carboxaldehyde." These pyridyl-substituted thiazolin-4-one ligands were further involved in the copper-catalysed conjugate addition of ZnEt2 to 2-cyclohexenone,... 

Esters of -hydroxy- or )8-mercapto-AAs react with n-butyl isonitrile to give 5-substituted methyloxazoline (or thiazoline)-4-carboxylates in the presence of PdCla as a catalyst (74SC97). The enamine-protected AAs were also tranformed into oxazolidin-5-ones after reaction with alkyl chloroform-ates (Scheme 28) (75S724). 

Thiazolidine-2-thione, 3-allyl-, 56, 79 2-Thiazohne, 2-allylthio-, 56, 77 2-Thiazoline, 2-benzylthio-, 56, 82 2-Thiazoline, 2-cmnamylthio-, 56, 82 2 Thiazoline, 2 ethylthio, 56, 82 2-Thiazohne 2-mercapto-, 56, 77 2-Thiazoline, 2-methylthio-, 56, 82 2-Thiazohne, 2-(4-phenyl-l-buten-3-yl)-thio-, 56, 78... 

Retro-Hantzsch, mechanism of, 84, 85, 102 Rhodanine, alkylation of, 419 ambident reactivity of. 419 reaction with aryldiazonium salts, 419 reaction with halogenothiazoles, 79 Rice cultures, 135, 136, 137 Ring-chain tautomerism, 113 Ring opening, of A-2-thiazoline-5-one, 433 Ring transformation, 5 amino-A-4-thiazo-line-2-thione to 4-mercapto-imidazoline-2-thione, 399 5,5-diphenyl-2,4-thiazolidinedithione, to 4,5-diphenyl-A-4-thiazoline-2-thione, 37 3... 

The simple 2-amino-A2-thiazolines are strong bases, readily soluble in water. Hot concentrated hydrochloric acid opens the ring affording mercapto-alkylamines. 2-Amino-A2-thiazolines are tautomeric alkylation of 2-amino-A2-thiazoline occurs at the ring nitrogen atom (140), whereas alkylation of 2-monoalkylamino-A2-thiazolines occurs at the exocyclic nitrogen atom (141 Scheme 67). Reaction of 2-amino-A2-thiazoline with malonic esters... 

One of the most valuable methods for the preparation of A2-thiazolines is of this class. The reaction of 2-haloalkylamines (334) with thioamides, metal thiocyanates or carbon disulfide give 2-alkyl- or -aryl- (335), 2-amino- (336), and 2-mercapto- (337) A2-thiazolines, respectively (Scheme 218) (17CB804). A method derived from the last procedure leads to a convenient synthesis of 2-phenyl-A2-thiazolines (340) under very mild conditions and consists of the condensation between a-aminothiols (338) and thiobenzoylmercaptoacetic acid (339 Scheme 219) (74TL1863) (this method could be better classified under Type E, Section 4.19.3.2.5). 

Mercapto-methyl-thiazoline Allylglycidylether Mild cation... 

Thione groups can often be eliminated by oxidation probably the sulfinic acid is the intermediate. Sometimes the sulfinic acid can be isolated (e.g., 740 741), but more often it spontaneously loses SO2. In this way, thiazoline-2-thiones give thiazoles, l,2-dithiole-3-thiones 742 are converted into 1,2-dithiolylium salts 743, l,3-dithiole-2-thiones 744 into 1,3-dithiolylium salts 745, 1,5-disubstituted imidazole-2-thiones into imidazoles <2003JHC229>, and 3-mercapto-l,2,4-triazoles into the parent triazole <2006S156>. In the pyrazole series, 746 also loses an A-methyl group to yield 747. 

Hydroxy-, -amino-, and -mercapto-acylamines (272 Z = 0, NH, S) cyclize to give the respective oxazolines, imidazolines, and thiazolines 273 (Scheme 133). 

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