Thieno- -pyrroles, synthesis

Thieno[2,3-d ]pyrimidin-4(3 H) -one, 3-methyl-synthesis, 4, 1017 Thieno[2,3-d ]pyrimidin-4-ones synthesis, 4, 1017, 1018, 1022 Thieno[2,3-6]pyrrole, 5-aryl-synthesis, 6, 1009 Thieno[2,3-6]pyrrole, N-benzyl- H NMR, 4, 1042 UV spectra, 4, 1044 Thieno[2,3-c]pyrrole, N-ethyl-UV spectra, 4, 1044 Thieno[3,2-6]pyrrole, 5-aryl-synthesis, 6, 1009 Thieno[3,2-6]pyrrole, N-benzyl- H NMR, 4, 1041, 1042 lithiation, 4, 1051 UV spectra, 4, 1044 Thieno[3,2-6]pyrrole, 2,3-dihydro-desulfurization, 6, 984 oxidation, 6, 981... 

Thieno[3,2-6]pyrrole, 5-ethoxycarbonyl-acylation, 4, 1050 synthesis, 4, 1070 Thieno[3,4-c]pyrrole, 5,6-dihydro-synthesis, 6, 987... 

Thieno[3,2-6]pyrrole-2-carboxylic acid, 5-aryI-synthesis, 4, 819... 

PHC431, 2005PHC389) discussions. The specialized review (1993H601) surveyed the synthesis of 1,5-benzodiazepines with three-, four- and five-membered rings fused to different positions of the 1,5-benzodiazepine skeleton. Synthesis of DNA-interactive pyrrole[2,l-c][l,4]benzodiazepines (1994CR433) and medicinal chemistry aspects of the novel thieno benzodiazepine antipsychotic Olanzapine (1997MI1743) have been reviewed. 

Benzo[4,5]furo[3,2- ]pyrrole 86 and benzo[4,5]thieno[3,2- ]pyrrole 87 were used for the synthesis of new constrained aryl-substituted 4,4-difluoro-4-bora-3a,4a-diaza-r-indacene (BODIPY) dyes 86 and 89 <2000JOC2900>. Their fluorescence characteristics were investigated and compared with the unconstrained systems published by Burghart and co-workers (Scheme 8) <199881276, 1999JOC7813>. 

The first synthesis of the parent compound of the benzo[4,5]thieno[2,3-f]pyrrole ring system 387 <2003T1477> and its derivatives was accomplished using the same synthetic sequence (Scheme 42). Starting with 2-methyl-benzo[ ]thiophene-3-carbaldehyde 388, an intermediate 389 was obtained. Treatment of bromo compound 389 with sodium azide in ethanol led to the stable triazoline 390. 1,3-Dipolar cycloreversion of 390 was induced by a catalytic amount of />-TsOH to give the parent 2//-benzo[4,5]thieno[2,3-c]pyrrole 387. Alternatively, direct treatment of bromo compound 389 with excess ammonia furnished 387 in one step. Compound 387 was treated with di-/-butyl dicarbonate and 4-dimethylaminopyridine (DMAP) to give iV-BOC derivative 391. Reaction of 389 with... 

Another nonclassical heterocycle, thieno[3,4-cJpyrazole, was synthesized,109 utilizing the ability of mesoionic ring systems to act as 1,3 dipoles in cycloadditions.106 Condensation of JV-phenylsydnone (162) with dibenzoylacetylene formed 3,4-dibenzoyl-l-phenylpyrazole (163) (85%) with phosphorus pentasulfide in refluxing pyridine, this gave 85% of 2,4,6-triphenylthieno[3,4-c]pyrazole (164) [Eq. (44)]. The synthesis of 5-methyl-1,3,4,6-tetraphenylthieno[3,4-c]pyrrole is also described.107... 

Recently, the synthesis of 5-aryl-2-oxopyrrole derivative 210 as synthon for the highly substituted pyrrole 211 as starting compound for fused heterocycle 212 was published [56], Diethyl 6-bcnzyl-5-phenyl-6//-thieno[2,3-/ ]pyrrolc-2,4-dicarboxylatc 212 was prepared from ethyl l-benzyl-5-chloro-4-formyl-2-phcnyl-l //-pyrrolc-3-carboxylate 211 and ethyl 2-sulfanylacetate in refluxing ethanol (Scheme 41). 

Synthesis of the parent 5//-thieno[2,3-c]pyrrole (17) is summarized in Scheme 24 <86CC310>. Knoevenagel condensation of the aldehyde (311) with diethyl malonate gave compound (312) (98% yield) and bromination (NBS-dibenzoyl peroxide) afforded the bromide (313) (80% yield). Treatment of this bromide (313) with sodium azide in aqueous ethanol at room temperature produced the azide (314) (92% yield), which with triphenylphosphine in THF formed (315), hydroly-... 

Reductive deoxygenation of nitrostyrylthiophenes using triethyl phosphite at 180 °C represents a facile and general synthesis of 5-arylthieno[2,3-Z>]pyrroles and thieno[3,2-6]pyrroles via reactive azene intermediates (equation 45) (73S313). 

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