Thieno 2,3-d imidazoles

Bicyclic 5-5 Systems Three Heteroatoms 1 2 Table 3 l//-Thieno[2,3-d]imidazoles and 3//-thieno[2,3-d]imidazoles. 

Tetrazoles and thiophenes belong to a prevalent class of five-membered heterocycles used as building blocks in synthetic chemistry. Soares and coworkers have described a microwave-assisted thermolysis of 1-(thiophene-2-yl)-lH-tetrazoles 48 (201ST(71)3343) giving access to thieno[2,3-d]pyrimidines 50, next to traces of thieno[2,3-d]imidazoles 49. Thiophenes 48 bearing a variety of substituents at their 3-, 4-, or 5-position gave access to thieno[2,3-d]-imidazoles 50 in high yields in short reaction times, as compared to conventional thermolysis (165 °C, 2 h) (Scheme 12). 

So wird aus l-Benzyl-4-brom-5-formyl-2-phenyl-imidazol und Natriumazid in 52% Ausbeute 4-Azido-l-benzyl-5-formyl-2-phenyl-imidazol erhalten, wahrend die Umsetzung von 1-Benzyl-4-brom-5-formyl-imidazol kein definiertes Produkt liefert922 Mit Mercapto-essigsaure-cthyl-ester und Natriummethanolat reagieren 1-substituierte 4-Brom-5-formyl-imidazole unter nukleophiler Substitution des Brom-Atoms durch den Thiolat-Rest und anschlieBender Kon-densation der Methylen-Gruppe mit der Aldehyd-Funktion zu den entsprechenden 2-Ethoxy-car bon yl-4H-[Pg.165]

Additional examples using urea include the following 2-amino-l-cyano-naphthalene for benzo[/]quinazolines (see32)169 3-amino-4-cyanopyrazole (see 15) for pyrazolo[3,4-d]pyrimidines (see 16)118,170 a 4-amino-5-cyano-imidazole (see 18) for a purine171 and 2-amino-3-cyanothiophene (see 11) for a thieno[2,3-d]pyrimidine (see 12).172... 

Monocyclic and Bicyclic aromatic heterocycles such as imidazoles, thiazoles, thiadiazoles, oxazoles, oxadiazoles quinazolines, indoles, benzimidazoles, purines pyrido[43-d]pyri-midines, thiazolo[5,4-d]pyrimidines, thiazolo[4,5-d]pyrimidines, oxazolo[5,4-d]pyrimi-dines and thieno[2,3-d]pyrimidines are renowned pharmacophores in drug discovery. These special structures are well explained and exemplified in chemical compound libraries. In this chapter, several types of thiazole based heterocyclic scaffolds such as mono-cyclic or bicyclic systems synthesis and their biological activities studies are presented, which are not frequently present in books and reviews. We mention the first importance of synthetic route of various thiazole based compounds and their applications in medicinal chemistry in this chapter. 

Pyrazole-, Thiazole>, and Imidazole>fused Thiophens.—Starting from (410) and carrying out nucleophilic substitution with thioglycolate followed by ring-closure, as described for (384) and (408), the thieno[2,3-d]pyrazole system (411) was synthesized. Their ionization constants have been determined and the transmission of the influence of the substituents R has been studied and found to be more feeble than in naphthalene d benzo[b]thiophen. From the cyano-derivative (412), thiophen-fused derivatives such as (413) and (414) have been synthesized. Electrophilic... 

The chemical structure of biotin (hexahydro-2-oxo-IH-thieno [3,4-d] imidazol-4-valeric acid) is shown in Fig. 1. Of the eight stereoisomers, only d-(+)-biotin occurs naturally and is biologically active. 

The copolymer, poly(lH-thieno[3,4-d]imidazol-2(3H)-one-co-3,4-ethylenedioxthio-phene), was also electrochemically prepared. 

D-(+)-Biotin (hexahydro-2-oxo-lH-thieno[3,4-d]imidazole-4-pentanoic acid) [58-85-5] NI... 

FACTORS FACTORS (vitamin) 1 H-THIENO(3,4-d)IMIDAZOLE-4-PENTANOIC ACID, HEXAHYDRO-2-OXO-, (3aS-(3a-a-4-p, 6a-a))- VITAMIN H... 

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