Pyrrolo cinnolines

Pyrrolo[2,1 -c][l, 4]benzodiazepines synthesis, 7, 614 Pyrrolo[l, 6]benzodiazocines synthesis, 7, 515 Pyrrolo[3,4-c]benzopyrazoles reactions, 6, 1034 Pyrrolobenzothiazoles synthesis, 4, 785 Pyrrolo[l, 2-c]benzotriazines synthesis, 4, 240 Pyrrolo[3,4-c]cinnolines synthesis, 4, 240... 

H(22)2269]. In fact, compound 170e coupled with the activated phenyl to give the pyrrolo[3,2-c]cinnoline 173, while compound Ic still coupled with the 4-position to give the pyrrolo-pyridazine 169c. 

Intramolecular diazonium coupling occurs upon treatment of l-(2-aminophenyl)- and 3-(2-aminophenyl)-pyrrole with nitrous acid to produce pyrrolo[l,2-c]benzotriazines and pyrrolo[3,4-c]cinnolines, respectively (B-77MI30502). Intramolecular arylation of the pyrrole... 

An unexpected reaction which leads to pyrrolo[3,4-c]pyridazines is the action of acid on the 3-diazopyrrole (106), obtained from the corresponding amine. Although pyrrolocinnolines were the target compounds, the pyrrolopyridazine (107) was obtained (60%) (Equation (32)) <84H(22)2269>. However, the cinnoline product is obtained when the carbethoxy group is present instead of the acyl group at position 4 <83H(20)255>. 

On irradiation of the zwitterionic pyrrolo[ 1,2-6]cinnoline 281 in ethanol, Ames et obtained the pyrrolo[2,l-i>]quinazolinone 95. 

The past year has seen the publication of Comprehensive Organic Chemistry, one volume of which contains much information on the six-membered ring systems to be reviewed in this article a monograph on the chemistry of condensed pyrazines has also appeared. Reviews on 1,4-thiazines, l,3-benzothiazines," pyridazines, benzo[c]cinnolines, quinazolines, purines, pyrrolo[3,2-c]quino-lines, 1,10-phenanthroline and its complexes, polyaza-phenanthrenes, and 1,9- and 1,10-diaza-anthracenes have been published. Other specialist reviews are devoted to catalytic methods of obtaining pyridine bases pyridine N-oxides the stereochemistry of quinolizines, indolizines, and pyrrolizines benzothiazinone dioxides 2-quinazolones and their cyclic homologues (e.g. 

Many new pyridazine, cinnoline, and phthalazine syntheses relied on the use of hydrazine-based precursors. 4,5-Dihydro-3(2//)-pyridazinones were obtained by cyclization of hydrazine with Meldrum s acids <97SC3513>, and six-membered cyclic hydrazides 3 were obtained in very high diastereoselectivities by the coupling of azide-substituted bisfenol silanes) <97JOC5680>. PhSeBr-promoted cyclization of alkenyl phenylhydrazones led to tetrahydro-pyridazines <97T7311>, condensation of furofuranones and hydrazines led to pyrrolo[2,3-... 

Methylcinnolinium iodide (63) with ethyl p-nitrophenylacetimidate gave a single tricyclic product (64), the analysis and spectra of which were consistent with either 2-ethoxy-4-methyl-3-p-nitrophenyl-4/f-pyrrolo[3,2-c]cinnoline (64a) or the isomeric 2-ethoxy-4-methyl-l-p-nitrophenyl-4H-pyrrolo[2,3-c]cinnoline (64b) (EtOH, 20°C, 5h 68%). ... 

The intramolecular gold-catalyzed hydroarylation of alkynes is a well-established methodology, which allows the synthesis of a broad range of complex products. Some examples are the synthesis of A -tosyl-1,2-hydroquinolines [122], cinnoline derivatives [123], phenantrenes [124], coumarines [117], and pyrrolo[l,2-a]quini-... 

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