Thiazolyl thiourea

The reaction of 2-amino-5-nitrothiazole with (3-chloroethyl isocyanate gives the corresponding thiazolyl urea (137) (Scheme 90) (298). Other examples are given in Section V.l.B, where the preparation of thiazolyl-thioureas is discussed,... 

The infrared spectra of a set of 2-thiazolylthioureas are reported in Ref. 486. The ultraviolet spectra of l-aryl-3-(2-thiazolyl)thioureas are characterized by two bands of approximate equal intensity around 282 and 332 nm (492). For l-alkyl-3-(2-thiazolyl)thioureas these bands are shifted to 255 and 291 nm, respectively (492). The shape of the spectrum is modified further when l.l -dialkyl-3-(2-thiazolyl)thioureas are considered (491). Fragmentation patterns of various 2-thiazolylthioureas have been investigated (100, 493), some of which are shown in Scheme 158. Paper and thin-layer chromatography provide an effective tool for the analysis of these heterocyclic thioureas (494. 495). 

When desulfurized with Pb02, l-aryI 3-(4-p-tolyl-2-thiazolyl)thioureas yield the heterocyclic guanidines (262) (Scheme 159) (299, 496, 497). 

The sulfur atom of the thiocarbonyl group is a good nucleophile, and reaction between benzyl bromide and l-(2-thiazolyl)thiourea yields the isothiouronium salt (496). The sulfur atom may also be engaged in a chelate, as exemplified by the Cu chelate of 2-thioureido-4-methylthiazole (491). These chelates with metal ions were thoroughly studied in acidic, neutral, and alkaline media for 66 metal ions in order to define their analytical use. They are formed in the molar ratio of 1 2 for metal II compounds (498). 

An interesting rearrangement of the (4-methyl-2-thiazolyl)thioureas (263) has recently been reported (Scheme 160) (303). The reaction mechanism is currently under investigation. This reaction does not occur if the 4-methyl substituent in the thiazole ring of 263 is replaced by an hydrogen, which suggests an electrophilic attack on C-5 as the mechanism of this reaction. 

The preparation and spectroscopic properties (infrared, ultraviolet, NMR) of iV-alkoxycarbonyl-N -(2-thiazolyl)thioureas (268) have been studied by the Nagano group (78, 264). These compounds react with bromine in acetic acid or chloroform to give 2--alkoxycarbonylimino-thiazolo[3,2-h]thiadiazolines (Scheme 162), whose structures were established by mass spectroscopy, infrared, NMR, and reactivity patterns (481). 

Beyond pharmaceutical screening activity developed on aminothiazoles derivatives, some studies at the molecular level were performed. Thus 2-aminothiazole was shown to inhibit thiamine biosynthesis (941). Nrridazole (419) affects iron metabohsm (850). The dehydrase for 5-aminolevulinic acid of mouse liver is inhibited by 2-amino-4-(iS-hydroxy-ethyl)thiazole (420) (942) (Scheme 239). l-Phenyl-3-(2-thiazolyl)thiourea (421) is a dopamine fS-hydroxylase inhibitor (943). Compound 422 inhibits the enzyme activity of 3, 5 -nucleotide phosphodiesterase (944). The oxalate salt of 423, an analog of levamisole 424 (945) (Scheme 240),... 

N-(2-thiazolyl)dithiocarbamates are prepared by the action of carbon disulfide on 2-aminothiazoles (see Section III.3.C and Ref. 505). When refluxed with secondary amines these heterocyclic dithiocarbamates yield l,T-dialkyl-3-(2-thiazolyl)thioureas (261) (491). 

Some diarylthioureas have been treated with chlorosulfonic acid thus N-phenyl-A -(2-pyridyl)- and iV-phenyl-A -(2-thiazolyl) thioureas 394 and 395 afforded the corresponding 4 -sulfonyl chlorides. . /V-Phenyl-A -(2-pyridyl)-thiourea 394, unlike the analogous urea 391, did not yield the 2, 4 -disulfonyl chloride and only gave the 4 -sulfonyl chloride. The larger steric size of the sulfur as compared with the oxygen atom presumably caused too much steric hindrance at the ortho-position of the phenyl ring to permit disulfonation. ... 

The interaction of 2-aminothiazole and ethoxy carbonyl isothiocyanate in ethyl acetate gives no less than four products, separable by chromatography. The N-ethoxycarbonyl-N -(2-thiazolyl)thioureas (149), which predominate amongst them (ca. 40—50%), appear not to undergo further cyclization spontaneously to the bicyclic products (150) except in one case (when R = Ph), but this ring closure does occur at 180 C. In each case, thiazolo[3,2-a]-sym-triazine-4-thione-2-one (148) was isolated in 20—40% yield, while (151) and (152) arose as minor products. ... 

N-Afe.- [86107-97-3]. Methym -(,4-methyF5-nitro-2-thiazolyl)thiourea, 9CI C6H8N4O2S2 M 232.287... 

Dimethyl(2-methoxy-5-nitrobenzyl) sulfonium(l -I-), in H-00384 A,A-Dimethyl-A -(4-methyl-5-nitro-2-thiazolyl)thiourea, D-00870... 

A,A-Dimethyl-A -[5-nitro-4-(4-nitrophenyl)-2-thiazolyl]thiourea, D-00874 A,A-Dimethyl-A/ -[4-(4-nitrophenyl)-2-thiazolyl]thiourea, D-00875... 

Methyl-6-(l-methylethyl)-2-(2-pyridinylazo)phenol, M-00197 5-Methyl-2-( 1 -methylethyl)-4-(2-pyridinylazo)phenol, M-00198 A -Methyl-A -(4-methyl-5-nitro-2-thiazolyl) thiourea, in M-00208... 

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