4-Aryl-2,3-dihydro-177-pyrido

Reaction of 2-(arylmethyleneamino)pyridines 335 and styrenes in the presence of hydroquinone afforded 2,4-diaryl-3,4-dihydro-2/f-pyrido[l,2-n]pyrimidines 336 by means of an inverse electron demand Diels-Alder reaction (95MI10). Reaction of 2-(benzylideneamino)pyridines 337 and chloroacetyl chloride gave 2-aryl-4//-pyrido[l,2-n]pyrimidin-4-ones 338 (97JMC2266). 

Reaction of 2,3-dihydro-3-hydroxy-3-methyl- 240 (R = Me), or a mixture of 2,3-dihydro-3-hydroxy-3-aryl-57/-pyrido[l,2,3-dfe]-l,4-benzoxazin-5-ones 240 (R = Ar) and (8-aroylmethoxy)quinolin-2(l//)-ones 241 (R = Ar) with ethyl 2-(bromomethyl)acrylate in the presence of activated Zn and hydroquinone gave 8-[(2,3,4,5-tetrahydro-4-methylidene-5-oxo-2-furanyl)-methoxy]quinolin-2(l//)-ones (242) (97HCA1161). 6,7-Dihydro derivatives of 240 reacted similarly (00HCA349). 

Het)aryl-l,4-dihydro-l,8-naphthyridin-4-ones 288 were obtained by heating 2-(het)aryl-4//-pyrido[l, 2-a]pyrimidin-4-ones 287 at 350 °C (97JMC2266, 99JMC4081) and in Dowtherm A at 220-240 °C... 

Zohuri et al. (2013) synthesized novel 2,9-dihydro-2-oxo-4-aryl-l//-pyrido[2,3-fc] indole-3-carbonitrile derivatives by condensation of substituted (triethoxymethyl) arene, l-methyl-lH-indol-2-ol, and cyanoacetamide using catalytic amounts of crosslinked poly(2-acrylamido-2-methyl propane sulfonic acid) (AMPS) as an efficient and heterogeneous catalyst (Scheme 2.10). This polymeric solid acid catalyst is stable and can be easily recovered and reused without significant change in its... 

Characteristic H NMR data of (4a/ ,55)- and (4n5,5R)-2-substituted 5- [A-(/e/ /-butoxycarbonyl)-L-tryptophyl]amino perhydropyrido[l,2-c]pyri-midine-l,3-diones were tabulated (01JMC2219). C CPMASS NMR data of 4-(4-methoxyphenyl)perhydropyrido[l,2-c]pyrimidine were reported (00JST73). C NMR data were reported for eight 4-aryl-2,3,5,6,7,8-hexahydro-l//-pyrido[l,2-c]pyrimidin-l,3-diones in the solid state and in CDCI3 solution (00JPO213). The structure of 4-aryl-3,4-dihydro-2//-pyrido [l,2-c]pyrimidine-l,3-diones and their 2,3,5,6,7,8-hexahydro derivatives were characterized by H and C NMR data (99JHC389). Conformational analysis of 6-methyl-2,3,4,6,7,ll/)-hexahydro-l//-pyrimido[6,l-n]isoquino-lin-2-ones 138 and 139 were carried out by H and C NMR studies (97LA1165). 

Cyclocondensation of a-aryl-2-pyridylacetamides and 2-(3,4-dihydroiso-quinolin-l-yl)acetamide with Et2C03 in the presence of NaOEt in boiling EtOH afforded 4-aryl-2,3-dihydro-l//-pyrido[l,2-c]pyrimidine-l,3-diones (99JHC389) and 6,7-dihydro-4//-pyrimido[6,1 -a]isoquinoline-2,4-dione (98MIP15), respectively. 

The respective amide was prepared from 7-substituted 5-oxo-2,3-dihydro-5//-pyrido[l,2,3-de]-l,4-benzoxazine-6-carboxylic acids via acid chlorides with different benzylamines (00M1P3). 6-Carboxamides were N-benzylated, and a side-chain phenolic hydroxy group was O-alkylated. 7-Aryl-5-oxo-2,3-dihydro-5//-pyrido[l, 2,3-r/e]-1,4-benzoxazine-6-carboxylic acid was obtained from the ethyl ester by alkalic hydrolysis. 

Oxidation of 7-hydroxy- and 7-aryl-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- f< ]-l,4-benzothiazine-6-carboxylates and 6-carboxamides with 3-chloroper-oxybenzoic acid in CH2CI2 yielded sulfoxides and sulfones, depending on the molar ratio of the substrate and oxidizing agent (00MIP7). A sulfoxide was prepared by the oxidation of ethyl (3S)-3-methyl-10-(2,6-dimethyl-4-pyridyl)-7-oxo-2,3-dihydro-7//-pyrido[l,2,3-<7c]-l,4-benzothiazine-6-carbox-ylate (OOMIPIO). 

Aryl-5-oxo-2,3-dihydro-5//-pyrido[l,2,3- e]-l,4-benzothiazine-6-carbox-amides and their 1,1-dioxides were prepared from the respective... 

Reaction of 2-cyanomethylpyridine with iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)-iV -(4-methylphenyl)carbodiimides, and with (1,1,2,2,2-pentachloro- and l,l-dichloro-2,2,2-trifluoroethyl)isocyanates or A-methoxycarbonyl-l,2,2,2-tetrachloro-, — l-chloro-2,2-trifluoroacetaldehyde imines afforded 3-aryl-4-cyano-l-(4-methylphenyl)imino-3-trifluoromethyl-2,3-dihydro-17/-pyrido[l,2-f]pyrimidines and 4-cyano-3-trichloro-, 4-cyano-3-trifluoro-17/-pyrido[l,2-4pyrimidin-l-ones, respectively <2004CHE47>. Refluxing 2-cyanomethylpyridine and iV-(l-aryl-l-chloro-2,2,2-trifluoroethyl)isocyanates in benzene furnished l-aryl-4-cyano-l-trifluoromethyl-l,2-dihydro-3//-pyrido[l,2-4pyrimidin-3-ones. However, when the solution of the isocyanate was added dropwise to the solution of 2-cyanomethylpyridine, and the reaction mixture was then treated with NEt at room temperature, the isomeric 3-aryl-4-cyano-3-trifluoromethyl-2,3-dihydro-l//-pyr-ido[l,2-dpyrimidin-l-ones were obtained. Reaction of l-(acetyl- and benzoylmethylene)-6,7-dimethoxy-l,2,3,4-tetra-hydroisoquinolines with PhCONCS yielded 1-acetyl-, 1 -benzoyl-9,10-dime thoxy-3-pheny 1-6,7-dihydro-2//-pyrimido[6,l- ]isoquinoline-2-thiones <2003SL2369>. 

Thermolysis of 3-alkyloxy- and 3-aroyloxy-5-phenyl-l,2,4-pyrrolo[l,2- ]quinoxaline-l,2,4-triones afforded 5-phenyl-9-(4-phenyl-3-oxo-3,4-dihydro-2-quinoxalinyl)-6,8,10-trioxo-5,6,9,10-tetrahydro-87/-pyrido[l,2-tf ]quinoxaline-7,9-dicarboxylates <2000CHE615, 2004CHE1295> and 7-aroyl-8-aroyloxy-5-phenyl-9-(4-phenyl-3-oxo-3,4-dihydro-2-quinoxalinyl)-5,6-dihydro-1077-pyrido[l,2- ]quinoxaline-6,10-diones <2002CHE498>, respectively. Thermolysis of 3-aryl-2-(5-aryl-2,3-dioxo-2,3-dioxo-4-furanyl)quinoxalines gave 7-aroyl-8-aroyloxy-6-aryl-9-(3-aryl-2-quinoxalyl)-10/7-pyrido[l,2- ]quinoxalin-10-ones <2001CHE1314, 2002RCB850>. 

Phenyl-l,2,3,6-tetrahydropyrido[2,l- ][l,3]thiazino[3,2- ]quinolin-6-ones were prepared by the reaction of 2-mercapto-5-phenyl-l,4-dihydroquinolin-4-ones with 1,3-dihalopropane <1997JAK97/278780>. 7-Acetyl-2-aryl-9-cyano-6-methyl-8-phenyl-3,4-dihydro-277,877-pyrido[2,l- ][l,3]thiazin-4-ones were obtained from 5-acetyl-3-cyano-6-methyl-4-phenyl-l,2,3,4-tetrahydropyridine-2-thione with 3-aryl-2-propenoyl chloride <2002CHE761>. Reaction... 

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>. 

Reduction of 3-aryl-4-oxo-4//-pyrido[2,l-fl]phthalazine-l-carboxamides with sodium cyanoborohydride in acidified methanol or lithium borohy-dride in tetrahydrofuran afforded 6,7-dihydro derivatives 47 (R = H) (88EUP294599). 

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