Pyrido quinoline, synthesis

H,4H-Oxazolo[5,4,3-y]pyrido[3,2-g]quinolin-4-one, 8-hydroxymethyl-6-methyl — see Nybomyein 5H-Oxazolo[2,3-[Pg.731]

When 3-phenyl-3//-triazolo[4,5-/]quinoline was heated at 390 00°C, IH-pyrido[2,3-c]carbazole 149 originated. Its structure could be confirmed by unambiguous synthesis from the 8,9,10,1 l-tetrahydro-7//-pyrido[2,3-c]carbazole (52CJC711). 

The yellow colored, sparcely soluble 5-ethyl-2-methyl-l l/f-pyrido[3,4-u] carbazolium 347 isolated from Aspidosperma gilbertii exists as a hydroxide after filtration of the corresponding iodide over basic aluminum oxide. A short synthesis was described (80CB3245). The Pyrido[3,4-a]carbazole ring system is present in the alkaloid AG-1, whereas Cryptolepine (348) possesses the indolo[3,2-b]quinoline moiety (65MI1). 

Perhydro derivatives of pyrido[l,2-7)][l,2]oxazines are frequently applied in the total synthesis of various alkaloids to control the stereochemistry, and pyrido[l,2-c][l,3]oxazines and [l,3]oxazino[3,4-u]quinolines were also used in the stereoselective syntheses of different alkaloids. Perhydropyrido[l,2-c][l,3]oxazines and their benzologs are formed form 2-(2-hydroxyethyl) piperidines and from their benzologs to justify the stereochemistry of 2-(2-hydroxyethyl) derivatives. Different optically active pipecolic acids can be prepared via 4-phenylperhydropyrido[2,l-c][l,4]oxazin-l-ones. 

Reaction of pyridines with dialkyl acetylenedicarboxylates in the presence of isocyanates in dry CH2C12 at room temperature produced 1-substituted 2-oxo-l,9a-dihydro-2/7-pyrido[l,2-tf]pyrimidine-3,4-dicarboxylates <2004TL1803>. One-pot, three-component synthesis of 1-substituted 2-oxo-l,llb-dihydro-2//-pyrimido[2,l- ]iso-quinoline-3,4-dicarboxylates and 4-(3-chloro-4-methylphenyl)-3-oxo-4,4a-dihydro-3/7-pyrimido[l,2-tf]quinoline-l,2-dicarboxylate was realized by the reaction of isoquinoline and quinoline with isocyanates and dialkyl acetylenedicarboxylates <2004S861>. Diastereomeric mixtures of l-tosyl-2-aryl-l,llb-dihydro-2/7-pyrimido[2,Ttf]isoquinoline-3,4-dicarboxylates were obtained from isoquinoline, iV-tosyl-benzaldehyde imines, and DMAD <2002OL3575>. 

Synthesis of the ortho- and peri-fused pyrido[3,2,l- 1[l,3,2]benzodiazaphosphorine ring system was accomplished from the quinoline carboxamide derivative 197 by treatment with phosphoryl chloride <1978JHC1169, 1979JHC897>. The iV-chloropropyl derivative 198b could be transformed to the tetracycle 199 (Scheme 27) <1979JHC897>. 

A search of the literature from 2006-7 reveals a large number of reports regarding the biological activities of this type of system, for example the synthesis and antiproliferative evaluation of certain pyrido[3,2-g]quinoline derivatives has been reported <2006BMC7370>. 

Interaction of substituted dienediamines with ethylenediamine yields im-idazo[3,2-n]pyridine derivatives (95JHC477). 3-Arylaminoindoles, with distinct enamine properties, are the starting materials for the synthesis of indolo[3,2-b]quinoline derivatives [96KFZ(7)42]. a-Carboline derivatives can be obtained from enamine-based 3-dimethylamino-2-indolinones [96KFZ(9)35, 96KFZ(10)32], The synthesis and transformation of enamines based on the pyrido[l,2-n]pyrazine ring system into imidazo[l,2-n]pyridine and imidazo[l,2-a]pyrimidine derivatives have been reported... 

Selig, P. and Bach, T. (2006) Photochemistry of 4-(2 -aminoethyl) quinolones enantioselective synthesis of tetracyclic tetrahydro-laH-pyrido [4, 3 2,3]-cydobuta[l,2-c] quinoline-2,11 (3H, 8H)-diones by intra- and inter-molecular [2 + 2] photocydoaddition reactions in solution. Journal of Organic Chemistry, 71, 5662—5673. 

Selig P, Bach T (2006) Photochemistry of 4-(aminoethyl)quinolones Enantioselective synthesis of tetracyclic tctrahydro-1 af/-pyrido[4, 3 2,3]cyclo-buta[l,2-c]quinoline-2,11(377,877)-diones by intra- and intermolecular [2+2]-photocycloaddition reactions in solution. J Org Chem 71 5662-5673... 

Pyrido[2,3-h]indoles (a-carbolines), synthesis and reactivity of 84KGS435. Pyrido[2,3-c]indoles (/S-carbolines), biochemistry of 83MIIO. Pyrido[3,2-c]indoles, tetrahydro- (tetrahydro-y-carbolines) 73KGS291. 3//-Pyrrolo[2,3-c]quinolines 78H(9) 1617. 

The Wittig-type reactions of iminophosphoranes with isocyanates and related compounds have also been extensively used in heterocyclic synthesis. Examples include the preparations of the mesoionic [l,3,4]thiadiazolo[2,3-c][l,2,4]triazines (210) from (209), 0 bicyclic guanidines, e.g. (212), from (211), naphthypyridines (215), (216), and (217) from (213) and (214), 2 pyrido[l,2-f]pyrimido-[4,5-d)pyrimidines (218), 7H-pyrido-[4,3-c]- (219) and 10H-pyrido[3,4-b]- (220) carbazoles, tricyclic fused 2,4-diimino-l,3-diazetidines (222) from the bisiminophosphorane (221), benzotriazepines (225) from (223) and (224), 6 and mesoionic thiazolo-[2,3-b]-1,3,4-thiadiazoles (227) and N,N-bisheteroarylamines from the iminophosphorane (226), derived from 3-amino-4-phenylthiazole-2(3H)-thione. The carbodiimides (229), prepared from the iminophosphorane (228), can be converted into quinolines or a-carboline derivatives depending on the nature of the isocyanate used in the reaction with (228) and the reactions of iminophosphoranes (230) and (231) with aryl and styryl isocyanates provide one-pot syntheses of quinoline, a-carboline, and quinindoline derivatives. 9... 

Microwave-assisted solvent-free synthesis of pharmacologically important pyrido fused-ring systems has recently been accomplished and is an improved method for assembly of a variety of pyridopyridazine and quinoline derivatives. Benz-1,3-oxazine formation has also been investigated in dry media using AI2O3-KF as a solid base (Scheme 8.75) [187]. 

Some time ago the Streith ring-expansion of pyridinium AT-imides was extended to the synthesis of lf/-l,2-benzodiazepines from quinoline N-imides. The full report has now appeared of the further extension of this valuable synthetic route to the preparation of the following previously unknown 1,2-diazepines, annelated to heteroaromatic rings pyrido[3,2-c]-,pyrido[2,3-c]-,thieno[2,3-c]-, thieno[3,2-c]-, and furo[2,3-c]-l//-l,2-diazepines e.g., (61) from (59), presumably via (60)." A similar attempt to prepare pyrrolodiazepines was not successful. These 1//-tautomers were converted into the 3//-l,2-diazepines by reduction with lithium aluminium hydride and then dehydrogenation with 4-phenyl-l,2,4-triazoline-3,5-dione. ... 

Myriad examples are known of oxindoles reacting to form indoles without prior carbonyl activation. Given (he vast scope of this subject, only a few early examples will be cited in addition to recent studies. Several groups have annulated oxindoles to access fused-indole heterocycles. Ila, Junjappa, and coworkers prepared pyrido[2,3-( ]indoles [61, 62] and 67/-indolo[2,3-fc]quinolines [63] using this approach (Scheme 9, equation 1). Adib and colleagues reported a simple synthesis of 9/7-pyrimido[4,5-Z ]indoles from oxindoles (eqnation 2) [64], and Bazgir and coworkers described a four-component one-pot a-carboUne synthesis... 

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