Imidazole l-methyl

The l-acyl-3-methylimidazole-2-thiones are easily obtained either from bis-l-methyl-2-imidazole disulfide, a carboxylic acid, and triphenylphosphine, or from 2-mercapto-l-methylimidazole and a carboxylic acid chloride in the presence of triethylamine.[32 ... 

COMPLEXES OF 1,3-DIHYDRO-l-METHYL-2//-IMIDAZOLE-2-THIONE WITH COBALT(H)... 

Bis(l,3-dihydro-l-methyl-2//-imidazole-2-thione)dinitratocobalt(II) is a deep-blue, crystalline solid. The Co—S contact is characterized by perturbation of the thioamide (IV) band of the parent ligand (730-740 cm 1) and by a v(Co—S) band at 315 cm-1. The complex is non-conducting in nitromethane. 

CoNAS2C,H 2, Cobalt(ll), bis(l,3-dihydro-l-methyl-2//-imidazole-2-thione)dinitrato-, 23 171... 

The S,N-containing hetranocyclic molecule l,3-dihydio-l-methyl-2 -imidazole-2-thione (mimt), together with its thiol tautomer, have significant coordination potential which is likely to be susceptible to variations in pH and other reaction conditions. 

Imidazole, l-methyl-2-nitro-pK, 5, 384 (B-76M14070I, 70AHC(I2)I03, 80AHC(27)24I)... 

Imidazole, 1 -methyl-5-nitro-2-styryl-ozonolysis, 5, 437 Imidazole, l-methyl-2-phenyl- C NMR, 5, 354 Imidazole, l-methyl-4-phenyl- C NMR, 5, 355 Imidazole, 2-methyl-4-phenyl-acylation, 5, 402... 

Imidazole, l-methyl-2,4,5-triphenyl-photochemical addition reactions, 4, 421 Imidazole, nitro-applications, 5, 498 IR spectra, 5, 358 mass spectra, 5, 359 quatemization, 5, 386 reactions, 5, 441 reduction, 5, 441 UV spectra, 5, 356 Imidazole, 1-nitro-reactions, 5, 454 Imidazole, 2-nitro-, S, 415 applications, 5, 498 reactions, 5, 96 reduction, 5, 441 synthesis, 5, 378, 395 Imidazole, 4-nitro-deuteration, 5, 417 methylation, 5, 383, 388, 389... 

To a solution of methyl 3-oxobutanoate 127 (580 mg, 5 mmol) and l-methyl-2-methylthio-l//-imidazole-5-carboxaldehye 128 (390 mg, 2.5 mmol) in 5 mL of absolute methanol was added a solution of ammonium hydroxide (25%, 0.4 mL). The reaction was heated at reflux overnight before cooling to room temperature and removing the solvent. The crude product was purified by preparative TLC to afford 526 mg of dimethyl l,4-dihydro-2,6-dimethyl-4-(l-methyl-2-methylthio-5-imidazolyl)-3,5-pyridine-dicarboxylate 129 (60%) as a solid, mp = 200-201 °C (MeOH). 

Tetraazafulvalenes bearing two pyrazole subunits could be prepared by an original way. Tlius, treatment of benzylidene acetophenone with iso-pentylnitrite leads to an A, A -dihydroxy-bipyrazolyl-A, A -oxide, which in turn can be oxidized to TAF of type 100 (72CC961, 79JOC3211). Another type of oxidative dimerization was observed by the reaction of the electron-rich l-methyl-2,4-bis(dimethylamino)imidazole with silver salts (83TL3563). A bis-cation was isolated in 30% yield in the presence of sodium tetrafluo-roborate an unsymmetrical structure 101 was predicted from its NMR data (Scheme 40). 

This trend is also observed in the reactions with nitrogen- and carbon-centered nucleophiles (2001H425). Thus, the reaction of 109 with sodium indolyl in DMF affords methyl 2-(indol-l-yl)indole-3-carboxylate (188, 77%). In better yield, 2-(indol-l-yl)indole-3-carbaldehyde (189, 95%) is formed in the corresponding reaction (99H1157) of 115a (Scheme 28). Sodium imidazolyl reacts with 109 in DMF at 60°C to afford methyl 2-(imidazol-l-yl)indole-3-carboxylate (190,28%), methyl indole-3-carboxylate (191,11 %), and unreacted 109 (36%). In contrast, under the same conditions, 110 and 115a provide higher yields of methyl 2-(imidazol-... 

Amino-l,5-dihydro-l-methyl-4//-imidazol-4-one, c302 2-Aminodiphenylamine, pi37 Aminodiphenylmethane, d761 Aminoethane, e63... 

Generally, the intermolecular Heck reaction between 2-iodo-, 4-iodo- and 5-iodo-l-methylimidazoles and olefins suffers from low yields (< 25%). Therefore, these transformations are of limited synthetic utility [29]. In one case, variable yields for adduct 62 (15-58%) were observed for the Heck reaction of 5-bromo-l-methyl-2-phenylthio-lf/-imidazole (61) and a large excess of methyl acrylate [42]. 

A mixture of l-methyl-2-methylthio-4,5-dihydro-l //-imidazole and diethyl malonate was heated for 54 hr to give diethyl (1 -methyl-2-imidazolidi-nylidene)malonate (471, R = H, R1 = Et) in 56% yield (86CB2208). 

Method C l-Methyl-3W-imidazol-2-thione (5.7 g, 0.05 mol), the haloalkane (0.05 mol), and TBA-Br (0.97 g, 3 mmol) in aqueous NaOH (40%, 15 ml) are added to PhH (I50ml) and the mixture is stirred for ca. 6 h at 60 °C. The organic layer is separated, dried over molecular sieves, and evaporated. The imidazolyl thioether is isolated by distillation under reduced pressure. 

Methimazole Methimazole, l-methyl-2-imidazolthiol (25.2.5), is synthesized by reacting aminoacetic aldehyde diethylacetal with methylisothiocyanate and snbseqnent hydrolysis of the acetal group of the resulting disubstituted urea derivative 25.2.4 by a solution of sulfuric acid, during which a simultaneous cyclization reaction takes place, forming the imidazole ring of the desired methimazole [15,16]. 

Aus Methylamino-essigsaure-ethylester (Sarkosin-ethylester) bzw. 2-Methylamino-l-oxo-l-phenyl-ethan werden mit Dithiocarbonsaure-cyanimid-dimethylester 4-Amino-5-methoxycar-bonyl-l-methyl-2-methylthio-imidazol bzw. 4-Amino-5-benzoyl-l-methyl-2-methylthio-imidazol hergestellt303. 

Aus [l-Methyl-2-phenyl-2-(2-phenyl-hydrazino)-ethenyIamino]-malonsaure-methylester-nitril wird durch Kochen in Methanol in 68% Ausbeute l-Anilino-2-methoxycarbonyl-4-methyl-5-phenyl-imidazol erhalten328 ... 

Zur Losung von 30 mg (0,011 mmol) 4-Brom-5-methoxycarbonyl-l-methyl-2-methylthio-imidazol in 5 ml Tetrahydrofuran gibt man bei 0° 10 mg feuchtes Raney-Nickel (W-2). Dann ruhrt man 30 min. bei 20°, filtriert das Nickelsulfid ab und dampft zur Trockcne ein Ausbeute 24 mg (93%) Schmp. 91 94°. 

Bei der Umsetzung von l-Methyl-2-phenyl-imidazol mit Chlor und Triethylamin in Tetrachlor-methan bei — 30° gelingt sogar die selektive Einfiihrung eines Chlor-Atoms in die 5-Position in 90% Ausbeute zu 5-Chlor-l-methyl-2-phenyl-imidazolbA1. 

---