Pyrido indole

According to the Ring Index, the system is classified as pyrido-indole and numbered as in 6 (harmine = 7-methoxy-1-methyl-9 -pyrido[3,4-fc]indole). This is the nomenclature adopted by Chemical Abstracts, according to which a-carboline (5) is 9 -pyrido[2,3-6]indole, jS-carboline (6) is 9jy-pyrido[3,4-6]indole, y-carboline (7) is pyrido[4,3-6]indole, and S-carbohne (8) is 5jy-pyrido[3,2-fc]indole. 

Full -polarization in diradicals can give rise to zwitterionic products. First examples were studied in detail by Carpenter and coworker who investigated solvent effects on rates and product distribution in Myers-Saito cyclizations.64 Polar solvents and substitution patterns that stabilize either positive or negative charges (or both) favor the zwitterionic products. For example, the presence of a dimethylamino group leads to stabilization of cations and isolation of pyrrolo-quinolines, rather than pyrido-indoles from eneyne-carbodiimides, as reported by Wang and coworkers (Scheme 14).65... 

Carbodiimide, N-benzyl-AT-lithio-, 56, 210 Carbodiimides, o-styryl-, generation, electrocyclization, 57, 36 Carbodiimides, N-io-styryD-A -t/S-styryl)-, o-carbolines from, 57, 50 Carbodiimides, vinyl-, generation, uses in synthesis, 57, 36, 49 Carbolines, see entries under the appropriate Pyrido-indole names Carbon, as pivotal atom in... 

Figure 6.14 Detectors arranged in series [reproduced with permission from G.A. Gross and A. Gruter, J. Chromatogr, 592,271 (1992)]. Condition sample, heterocyclic aromatic amines column, 25cm x 4.6mm i.d. stationary phase, TSK gel ODS80,5 [xm mobile phase, 1 ml min waterwith 0.01 M triethylamine, pH 3.2 or 3.6, and acetonitrile, gradient UV 263 nm and fluorescence detectors. Peaks 1 and 5 = pyrido-imidazoles 2 and 4 —imidazo-chinolines 3, 6, 7, 8 = imidazo-chinoxalines 9, 10, 11, 13, 14 —pyrido-indoles 12 an imidazopyridine.

Tetrahydro-isochinoline1-7 — l,2,3,4-Tetrahydr-9H-(pyrido-indole) (1,2,3,4-Tetrahydro-/ -carboline)5,8... 

Many patents have been issued on the use of pyrogaUol derivatives as pharmaceuticals. PyrogaUol has been used extemaUy in the form of an ointment or a solution in the treatment of skin diseases, eg, psoriasis, ringworm, and lupus erythematosus. GaUamine triethiodide (16) is an important muscle relaxant in surgery it also is used in convulsive-shock therapy. Trimethoprim (2,4-diamino-5-(3,4,5-trimethoxybenzyl)pyrimidine) is an antimicrobial and is a component of Bactrin and Septra. Trimetazidine (l(2,3,4-trimethoxybenzyl)piperazine (Vastarel, Yosimilon) is used as a coronary vasodilator. l,2,3,4-Tetrahydro-6-methoxy-l-(3,4,5-trimethoxyphenyl)-9JT-pyrido[3,4- ]indole hydrochloride is useful as a tranquilizer (52) (see Hypnotics, sedatives, ANTICONVULSANTS, AND ANXIOLYTICS). Substituted indanones made from pyrogaUol trimethyl ether depress the central nervous system (CNS) (53). Tyrosine-and glycine(2,3,4-trihydroxybenzyl)hydrazides are characterized by antidepressant and anti-Parkinson activity (54). 

No systematic study of the mass spectra of pyridopyrazines has been noted, but those of 2,3-dialkyl and 2,3-diaryl derivatives have been recorded 750MS97), and mass spectrometry has been used in the elucidation of problems in the reactions of pyrido[2,3-f ]pyrazines with amide ion (including use of and derivatives) (79JHC305), and of pyrido[2,3-f ]pyrazinium salts with indoles (78ZOR431). The mass spectra of some 1-deazaflavins have been recorded (74JCS(P1)1965). 

Pyrido[ 1, 2 1,2]imidazo[4,5-b]quinoxaline nomenclature, 1, 22 2,2 -Pyridoin synthesis, 2, 337 Pyrido[ 1,2-6]indazoles synthesis, 5, 335 E ridoindoles rearrangement, 4, 508 Pyrido[a]indoles synthesis, 4, 233 Pyrido[6]indoles nomenclature, 4, 498 Pyridooxadiazolones ring contraction, 4, 149... 

AICI3, benzene or anisole, reflux, 25-91% yield, cleaved from a pyrido-[2,3-Z ]indole and indole. ... 

The MPM group was used in the preparation of a variety of triazoles, imidazoles, and pyrazoles. It is readily cleaved with CF3COOH at 65° (52-100% yield). It is also cleaved from a pyrido[2,3-Z ]indole with DDQ, 88% yield. ... 

For a structure-activity relationship study on 5//-pyrido[4,3-(j]indoles (y-carbolines), we needed both 1-unsubstituted 271 and 1-substituted methyl 2,3-dihydro-3-oxo-5//-pyrido[4,3-(j]indole-4-carboxylates 272 (Scheme 42). 

Thus, novel 2-substituted methyl 2,3-dihydro-l-methyl-3-oxo-5//-pyrido[4,3-/j] indole-4-carboxylates are available. Since the methyl group at the 1 position is expected to react with various reagents, many 1-substituted derivatives could be produced. 

Fischer indolization of 9-arylhydrazono-6,7,8,9-tetrahydro-4//-pyrido-[l,2-u]pyrimidin-4-ones 289 by heating in 85% phosphoric acid, or in PPA yielded 7,12-dihydropyrimido[l, 2 l,2]pyrido[3,4-Z)]indol-4(6//)-ones 290 (96JHC799, 99MI12, 00MI22). From the 3-ester and 3-carboxylic acid derivatives 289 (R = COOEt, COOH) and decarboxylated products 290 (R = H) were obtained. 

Triisopropylsilyl group of 2-[l-triisopropylsilyl-l//-indol-6-yl)perhydro-pyrido[l,2-u]pyrazine was removed by treatment with BU4NF in THF (01MIP5). 

Few heteroaryl-substituted 37/-azepines are known however, photolysis of 2-(2-azidophenyl)-pyridine (80) in diethylamine provides Ar,Ar-diethyl-3-(2-pyridyl)-3/f-azepin-2-amine(81), along with minor amounts of pyrido[3,2-6]indole (82) and the mesoionic pyridofl, 2-7>]indazole (83).191... 

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