Pyrrolo -1,2,3-triazoles

The l-aminobenzotriazoles are desirable as benzyne precursors. The dianion of N-boc-1-aminobenzotriazole 34 reacts to introduce electrophiles at the 7 position to give 35 in excellent yields <96TL5615>. Pyrrolo[l,2-c][l,2,3]triazoles 37 are formed by trapping... 

Some interesting fused 1,2,3-triazole ring systems have been reported. A series of 5-piperidyl-substituted 7-hydroxy-3f/-l,2,3-triazolo[4,5-d]pyrimidines 143 has been synthesized from pipecolinate esters, benzylazides, and cyanoacetamide <06CHE246>. 4-Alkylidene-5,6-dihydro-4//-pyrrolo-[l,2-c][l,2,3]triazoles 144 were prepared from alkylidenecyclopropanes via diiodogenation/Cu(I)-catalyzed 1,3-dipolar cycloaddition/intra-molecular Heck reaction sequence <06SL1446>. 6,6-Dimethyl-2-phenyl-4,5,6,7-tetrahydro-27/-benzotriazol-4-one 145 were prepared from A-(5,5-dimethyl-3-oxocyclohexenyl)-S,S-diphenylsulfilimine and... 

Several routes to the pyrrolo[l,2-f][l,2,3]triazole skeleton have been described. Intramolecular dipolar cycloaddition of azido-alkenes or alkynes seems to be the most convenient process, although the cyclization efficiency seems to be highly substrate dependent (Scheme 16) <2002JA2134, 2003T1477, 2005SL2187, 2005TL8639>. The formation of this bicyclic system by an intramolecular Heck reaction is an attractive alternative. The recent syntheses of sulfamides by intramolecular cyclization of alkenes or allenes offer a complementary route to the classical... 

Variation of the ring portion of acyclovir has been achieved. Compounds include monocyclic (isocytosine, triazole, imidazole), bicyclic (adenine, 8-azapurine, pyrrolo[2,3-c/]-pyrimidine, pyrazolo[3,4-[Pg.131]

Fusion of a 1,2,4-triazole ring to pyrrolo-benzodiazepine (1992JHC1005) and pyrrolo-benzothiadiazepine (1992SC1433) rings has been reported starting from 0X0 203 and included formation of the phosphonic imidate with formyl hydrazine (Scheme 42, Section 3.1.1.2). 

Finally, 5(4Ff)-oxazolones react as masked 1,3-dipoles with nitrileimines, l-nitroso-2-naphthol and [60]fullerene to give 1,2,4-triazoles, naphth[l,2-ci oxazoles and 5 -phenyl-2 7/-pyrrolo[3, 4 l,2][60]fullerene, respectively. 

Furo[2,3-cf]-1,3,2-dioxathioles Furo[3,4-d]-1,3,2-dioxathioles Furo[3,4-d]-1,2,3-triazoles Pyrrolo[2,3-cf]-1,2,3-triazoles Pyrrolo[3,4-d]-1,2,3-triazoles Thieno[3,4-d]-1,3,2-dioxathioles Reactivity of Substituents Attached to Ring Carbon Atoms... 

Heating of 1,2,3-triazolium-l-aminide 168 with acrylonitrile in dry acetone at reflux yielded a mixture of pyrrolo[2,3-similar reactions with different N-substituted maleimides produced only one product in each case. Table 6 summarizes the results of these reactions <2001J(P1)1778>. 

Pyrrolo[3,4- -1,2,3-triazoles are often synthesized by 1,3-dipolar cycloaddition of maleimides with azides. At-Methylmaleimide and azide 179 heated at reflux in dry toluene for 24-48h led to triazole 180 as a 1 1 mixture of diastereomers <2002JA2134>. Benzotriazol-l-ylmethyl azide 181 formed the cycloadduct 182 with At-methyl-maleimide after refluxing in toluene for 3h (Equations 34 and 35) <1996JHC335>. 

Pyrrolo[2,l-6]thiazoles,28,29,270-273 pyrrolo[l,2-a]imidazoles,38,274-277 pyrrolo[ l,2-a]benzimidazoles,38, 278-288 pyrrolol l,2-6]-s-triazoles,289 and pyrrolo[2,l-c]-s-triazoles290 have been prepared by this route. 

Heating 4-azidothiazoles having an imino or aldehyde group at the 5-position affords fused pyrazolo- and isoxazolo[3,4-d]thiazoles (Equation (7)). When an alkenyl group is in 5-position of the triazole ring, 4//-pyrrolo[2,3-[Pg.454]

Vilsmeier reaction, 4, 1051 Furo[3,2-6]pyrroles MO calculations, 6, 979 synthesis, 4, 1069 6, 1009 Furo[3,4-a]pyrrolo[2,1,5-cd]indolizine nomenclature, 1, 22 Furopyrylium salts, 4, 993-995 Furoquinolines biosynthesis, 4, 992 occurrence, 4, 988 pharmacology, 4, 992 reactions, 4, 988 synthesis, 4, 989 Furo[3,2-c]quinolines, 4, 991 Furo[3,4-fe]quinoxaline, 1,3-diphenyl-synthesis, 4, 993 Furoquinoxalines, 4, 992 Furo[2,3-6]quinoxalines synthesis, 4, 992 Furosemide toxicity, 1, 136 Furospinulosin UV spectra, 4, 587 Furospongin-I mass spectrometry, 4, 583 Furo[3,4-d][l,2,3]triazole, 2,6-dihydro-synthesis, 6, 996 Furo[3,4 -d][ 1,2,3]triazoles synthesis, 6, 996 Furoxan, 4-amino-3-aryl-tautomerism, 6, 404 Furoxan, 4-amino-3-methyl-synthesis, 4, 414 Furoxan, 4-aryl-3-methyl-rearrangement, 6, 408 Furoxan, 3-aryl-4-nitro-synthesis, 6, 414 Furoxan, 4-benzoyl-3-methyl-oxime... 

---