Thiazole-4-ones

Mesoionic thiazol-4-one, see 4-Hydroxy-thiazolium hydroxide inner salts Methanol, action on thiazolium salts, 32 Methine dyes, nonionic, nomenclature of, 27... [Pg.332]

The reaction of the biacetyl-trimethyl phosphite adduct (65) with acyl isocyanates has been extended to the isocyanates ROCONCO and PhCS-NCO.46 With the thiazolin-4,5-diones (66), (65) gave the thiazol-4-ones (67). [Pg.39]

Ph, R = H) and acetic anhydride-triethylamine was initially thought to be anhydro-2,3-diphenyl-4-hydroxy-l,3-thiazolium hydroxide, CijHiiNOS (114, R = R = Ph, R = H), but later studies established that the product had the molecular formula C30H24N2O2 and the constitution 116. The synthesis of the meso-ionic l,3-thiazol-4-one (114, R = R = Ph, R = H), orange-yellow needles, m.p. 113°-115°, was successfully achieved by dehydration of the acid (115, R = R = Ph, R = H) using acetic anhydride-triethylamine for a few minutes at room temperature. The acids (115, R = NR2, R = Ph, R = H) and acid anhydrides similarly yield the corresponding meso-ionic l,3-thiazol-4-ones (114, R = NRj, R = Ph, R = H). Analogous polycylic meso-ionic l,3-thiazol-4-ones have also been prepared. ... [Pg.26]

Alkylation of 5-phenylrhodanines (122) with alkyl iodides and sodium ethoxide yields the meso-ionic 2-alkylthio-l,3-thiazol-4-ones (114, R = SR) 78a structure of the compound 114, R = SMe, R = NHj, R = Ph, was established by X-ray analysis. The dipole moment of the compound 114, R = R = Me, R = Ph, in benzene solution is 5.21 D. Irradiation of the meso-ionic l,3-thiazole-4-thione (114, R = SMe, R = Me, R = Ph) in ethanol yields the isomeric 3-methyl-4-methylthio-5-phenyl-l,3-thiazol-2-one. A novel mechanism for this photochemical rearrangement has been proposed. ... [Pg.28]

A full account of the preparation and 1,3-dipolar cycloadditions of the meso-ionic l,3-thiazol-4-ones (114) has now been published. A detailed chemical and spectroscopic study of the stereochemistry of the 1 1 adducts of the l,3-thiazol-4-ones (114) with olefinic 1,3-dipolarophiles has been reported. ... [Pg.114]

Mesoionic 1,3-thiazole-4-ones of type 34 are known as thioisomiinchnones. As one of the mesomeric structures demonstrates, these species contain the structural fragment characteristic of thiocarbonyl ylides (61). A convenient access to thioisomiinchnones involves the reaction of /V-arylthiobenzamides with a-bromo-phenylacetyl chloride (62). [Pg.246]

U-Thiazol-4-ones (Anhydro-4-hydroxy-1,3-thiazolium Hydroxides)... [Pg.26]

A full account of the preparation and 1,3-dipolar cycloadditions of the meso-ionic l,3-thiazol-4-ones (114) has now been published.441... [Pg.114]

Irradiation of the adduct (178) obtained from benzyne and a mesoionic thiazol-4-one in benzene-methanol solution resulted in extrusion of sulphur and formation of the isoquinolone (179).108 This is in complete contrast with the... [Pg.495]

Lactams. Desulfurization of mesoionic thiazole-4-ones (1) with Raney nickel in CH3OH or THF results in ring contraction to /S-Iactams (2). ... [Pg.526]

Insuasty A, Ramirez J, Raimondi M, Echeverry C, Quiroga J, Abonia R, Nogueras M, Cobo J, Rodriguez MV, Zacchino SA, Insuasty B. S)mthesis, antifungal and antitumor activity of novel (z)-5-hetarylmethylidene-l,3-thiazol-4-ones and (z)-5-ethylidene-l,3-thiazol-4-ones. Molecules 2013,18, 5482-5497. [Pg.63]

Mukhopadhyay and Ray (2011) described the synthesis of 2-amino-5-alkyl-idenethiazol-4-ones from ketones, rhodanine, and secondary amines promoted by a silica-pyridine-based catalyst. Compounds containing a 2-amino-5-arylidene-l,3-thiazol-4(5H)-one moiety display a wide range of interesting pharmaceutical activities such as antiviral (Abdel-Ghani, 1999), antimicrobial (Soltero-Higgin et al., 2004), cardiotonic (Andreani et al., 1996), and anti-inflammatory (Nasr and Said, 2003) effects. The one-pot synthesis of thiazol-4-ones was optimized on a model... [Pg.30]

M. Anderluh, M. Jukic, R. Petrie, Tetrahedron 2009, 65, 344—350. Three-component one-pot synthetic route to 2-amino-5-alkylidene-thiazol-4-ones. [Pg.486]

C. Mukhopadhyay, S. Ray, Tetrahedron Lett. 2011, 52, 6431-6438. Rapid and straightforward one-pot expeditious synthesis of 2-amino-5-alkylidene-thiazol-4-ones at room temperature. [Pg.486]

A very detailed report on /3-lactams, both synthetic and natural, has been published." An excellent new method for the synthesis of a-amino-/8-lactams has been described." The central feature of the synthesis is the protection of a-amino-acids as an enamine followed by acid chloride formation and annellation of imines (Scheme 86). Yields are in the region 35—45%. An unusual transformation of mesoionic thiazol-4-ones into /8-lactams has been reported. It is... [Pg.305]

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