2-mercapto-imidazoline

Onr resnlts strongly indicate that the antithyroid drugs PTU (2) and N-Methyl-2-mercapto-imidazoline (MMI) have a different way of action. Thns, (2) together with NMBZT (4) forming weak S-I c.t. complexes (Table 13.1) may interfere either by inhibiting TPO activity or by inhibiting Deiodinase (ID-1) enzyme which is responsible for the formation of T3 from T4 hormone. 

AI3-16292 Akrochem etu-22 Aperochem ETU-22 CCRIS 298 4,5-Dihydro-2-mercaptoimidazole 4,5-Dihydroimidazole-2(3H)-thione EINECS 202-606-9 Ethylenethiourea Ethylene thiourea Ethylene thiouree I Ethylene thiouree 1,5Ethylene-2-thiourea 1,3-Ethylenethiourea ETU HSDB 1643 lmidazole-2(3H)-thione, 4,5-dihydro- Imidazolidinethione Imidazoline, 2-mercapto- Imidazoline-2-thiol 2-lmidazoline-2-thiol 2-lmidazolidinethione Imidazoline-2(3H)-thione Mercaptoimidazoline 2-Merkaptoimidazolin 2-... 

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... 

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. 

A strictly dehned region of chemical shifts of C2, C4, and C5 atoms in A-oxides of 4A-imidazoles allows to dehne clearly the position of the A-oxide oxygen atom (102). Chemical shifts of the a-C nitrone group in a-N-, O-, and S-substituted nitrones are located in the region of 137 to 150 ppm (388, 413). On the basis of 13C NMR analysis of 3-imidazoline-3-oxide derivatives, the position of tautomeric equilibria in amino-, hydroxy-, and mercapto- nitrones has been estimated. It is shown that tautomeric equilibria in OH- and SH-derivatives are shifted toward the oxo and thioxo forms (approximately 95%), while amino derivatives remain as amino nitrones (413). In the compounds with an intracyclic amino group, an aminonitrone (A) - A-hydroxyaminoimino (B) tautomeric equilibrium was observed (Scheme 2.76), depending on both, the nature of the solvent and the character of the substituent in position 2 of the heterocycle (414). 

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

Imidazolidine-2-thiones (or 2-ones) have been shown by NMR studies to exist entirely in these forms rather than as the possible 2-mercapto-(or 2-hydroxy-)2-imidazoIines (80CS(15)193). The thione structure for benzimidazolinethiones is supported by UV, IR and dipole moment measurements. In addition, an X-ray study of l-(j8-D-ribofuranosyl)benz-imidazoline-2-thione confirms its thione (59) rather than the thiol (60) structure (Scheme 19). 

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