Thiazoles 2-amino

Ethyl 2-(2-amino-4-thiazole)-2-methoxyiminoacetate, 2995b iV-Ethylaniline, 2989 Ethyl azide, 0868 Ethyl 2-azido-2-propenoate, 1884 f Ethylbenzene, 2963 f Ethyl bromide, see Bromoethane, 0842... 

Table VI-2 contains representative ultraviolet data for 2-amino-thiazoles and 2-iminothiazolines.

Thus in neutral medium the reactivity of 2-aminothiazoles derivatives toward sp C electrophilic centers usually occurs through the ring nitrogen. A notable exception is provided by the reaction between 2-amino-thiazole and a solution (acetone-water, 1 1) of ethylene oxide (183) that yields 2-(2-hydroxyethylamino)thiazole (39) (Scheme 28), Structure 39... 

Pyridine Substrate Peroxide (Source) Aniline+ NOOR A a B 2-Amino- thiazole NOOR ... 

The first peer-reviewed report on BMS-354825 was published in Science soon after the meeting presentations [128]. BMS-354825 has a 2-amino-thiazole core and is related to a series of Lck inhibitors from BMS based on this template [129] (Scheme 10). BMS-354825 potently inhibited the pro-... 

The incorporation of complex side chains at the 7 position based on alkyloximes of 2-amino-thiazole-5-gyloxylamides has provided drugs with very wide antibacterial activity that extend to hitherto resistant species such as pseudomonas. The preparation of one of the simpler side chains involves, first, the formation of the methyl ether from the oxime obtained by the nitrosation of methyl acetoacetate. Chlorination of the product, for example with sulfuryl chloride, gives the intermediate (21-1). The aminothiazole ring is then formed by reaction of that with thiourea to give (21-2). The free acid (21-3) is obtained by saponification of the product. The protected acid chloride (21-5) is obtained by sequential acylation of the amino group with chloroacetyl chloride and then reaction with thionyl chloride. 

The failure of the Tschitschibabin reaction has also been observed with other NH-aminoazoles. Werbel and Zamora214 found that 2-amino-1-methylbenzimidazole reacted rapidly with phenacyl bromide to give an intermediate that cyclized easily to the imidazo[l,2-a]benzimidazole, but 2-aminobenzimidazole gave no product. In the same way, 2-amino-thiazole yielded a bicyclic system but 3-amino-s-triazole did not.225... 

Several new syntheses of thiazoles from thioureas have been developed in recent years. Werbel95 was able to prepare 2-aminothiazoles by reaction of thioureas with bis(/3-chloroethyl) ether. 1,3-Disubstituted thioureas, however, yielded disubstituted 4-thiazolines. In a German patent, Rcisinger96 reported that 2-aminothiazole was formed in 88% yield from thiourea and vinyl acetate in the presence of sulfuryl chloride. A method for the preparation of the 4-hydroxy-2-amino-thiazole (47), which probably exists in the tautomer shown, has been developed by Delaby et al.97 via the reaction of thiourea with jS-acyl-acrylic acid or its esters. Zbiral98 has observed that acylvinylphos-... 

The secondary amino group of 3-(Al-ethylaminomethyl)-7-[2-(2-amino-thiazol-4-yl)-2-(Z-1 -carboxy-1 -methylethoxyimino)acetamido]ceph-3-em-3-carboxylic acid was arylated with 8-methylthiopyrido[l,2-a]pyrimidi-nium salt in dimethylformamide in the presence of triethylamine at 40°C (89MIP2). 

For example, amino-imidazoles and amino-thiazoles were also found to give a similar 3-CR product (Scheme 10.2). This experience inspired the idea of using combinatorial chemistry methods to find novel and unexpected reaction products and novel MCRs. 

W.G., Marathe, P., Bursuker, I., Kellar, K.A., Roongta, U., Batorsky, R., Mul-heron, J.G., Bol, D., Fairchild, C. R., Lee, F. Y., Webster, K. R. Discovery of amino-thiazole inhibitors of cyclin-dependent kinase 2 synthesis, X-ray crystallographic analysis and biological activities. Journal of Medicinal Chemistry 2002, 45, 3905-3927. 

The compound 3-(2-Bromoacetyl)-4-hydroxychromen-2-one (18) reacts with thiourea to afford 3-(2-amino-thiazol-4-yl)-4-hydroxychromen-2-one hydrobromide (19a). This reaction was carried out in boiling ethanol for 30 min. Compound 19a also gave positive coloration with iron(III) chloride solution (Scheme 7). In the reaction of compound 18 with 1-methylthiourea under identical experimental conditions as above, 4-hydroxy-3-(2-methyl-aminothiazol-4-yl)chromen-2-one (19b) in 67% yield was obtained. In a similar manner, 18 reacted with three arylthiourea derivatives affording the corresponding 3-(2-arylthiazol-4-yl)chromen-2-ones (19c-e) in different yields (70, 63 and 74%, respectively). The derivatives formed in these reactions were identified as 4-hydroxy-3-(2-phenylaminothiazol-4-yl)chromen-2-one(19c), 4-hydroxy-3-(2-p-tolylaminothiazol-4-yl)chromen-2-one (19d) and 4-hydroxy-3-2-(4-methoxyphenylamino)thiazol-4-yl)chromen-2-one (19e). The identities of these compounds were established by spectral data and elemental analysis. 

When the cyclization procedure, using hydrogen bromide, is applied to a-cyanoalkyl thiocyanates (152), the salts of 2-bromo-4-amino-thiazoles (153) can be obtained in excellent yield.105 Most of these salts... 

The reaction of arylsulfonylbenzimidoyl chlorides (99) with 2-amino-thiazole yields 100 (Scheme 69) (262). 

Most of the spectroscopic properties of 2-imino-4-thiazolines have been treated in Section II. Paper chromatography and thin-layer chromatography are particularly suitable for distinguishing 2-amino-thiazoles from 2-imino-4-thiazolines their Rfs and characteristic reactions are different (148, 494. 705). 

Chlorothioformic phenyl ester, with 2-amino-thiazoles, 51... 

Methyl iodide, reactions with dialkyl-amino-thiazoles, 32. See also Alkylation 4-Methylthiazole, preparation of, from Na/NH3 reduction of 4-methyl-A-4-thiazoline-2-thione, 397 2-Methylthio-3-methylthiazolium salts, as catalyst for methylthiothiazole rearrangement, 406 Methylvinylketone, reaction of, with... 

Schiff bases, 256-259, 268, 270 to amines. 40 from aminothiazoles, 98 with 2-amino thiazoles, 30, 40 complexes of, 99 cyclization to, 42 IR spectra of, 41 in reduction by AlLiH,. 14 in reduction by NaBH4, 14 LTV spectra of, 41 see also Thiazolylamidines Schistosomacidal, 141 Schistosomiasis japonica, 145 Schotten-Bauman reaction. 51. 123 Sedative, 145. 148,438 Selective herbicide, 135 Self association, effect of, on UV spectra of A-4-thiazoline-2-thione. 381 A-4-thiazoline-2-one, relation with protomery, 377... 

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