Synthesis of 5H-[1]benzopyrano[4,3-b]pyridin-5-ones containing an azacannabinoidal structure

Starting from 7-alkoxy-4-aminocoumarins 5,6,8,12 , and 13 as key intermediates, this paper describes two different methods for the preparation of azacannabinoidal 5H[1]benzopyrano[4,3-b]pyridin-5-ones 24–27, 38 , and 39 containing typical structural requirements for ZNS activity. First, Michael addition of 6 and 8 to the double bonds of alkyl vinyl ketones 14 and 15 resulted in a mixture of tetrahydropyridines 24–27 and fused pyridines 20–23 the latter of which were reduced by sodium cyanoborohydride to give the target compounds 24–27 . The second, pyridine ring closure was accomplished by a combination of Vilsmeier acetylation and formylation resulting in fused 4-chloropyridines 31–33 followed by reduction.     

Preparation of benzo[c][2,7]naphthyridin-5(1H)-ones as analogs of benzopyrano[3,4-c]pyridin-5-one bronchodilators

A series of 2,3,4,6-tetrahydro-8,9-dimethoxybenzo[c][2,7]naphthyridin-5(1H)-ones was prepared as potential anticholinergic bronchodilators. The naphthyridine ring system was constructed by cyclization of a 3-amido-4-piperidone. Alkylation with alkylaminoethyl chlorides or reductive amination of an intermediate methyl ketone yielded the final target compounds.     

Synthesis of 4-Halofuro[3,4-c]pyridin-3(1H)-ones from 2-Halopyridine-3,4-dicarbonitriles

Russian Journal of Organic Chemistry - Heating of 2-halopyridine-3,4-dicarboxylic acids in propionic anhydride led to the formation of 4-halofuro[3,4-c]pyridine-1,3-diones as a result of...     

Synthesis of a novel heterocyclic system: 8-Fluro- 1,2,3,4,4a,10a-hexahydro-5H-[1]benzopyrano[2,3-c]pyridin-5-ol

The Synthesis of the title compound is described and its structure elucidated by ¹H nmr spectroscopy.     

Synthesis of 5H[l]benzopyrano[3,4-b]pyridin-5-one and its derivatives

3-Aminocoumarin undergoes the Skraup reaction to give a new ring system, 5H[l]benzo-pyrano[3,4-b]pyridin-5-one (IVa). When 3-aminocoumarin was condensed with the ethoxy methylene derivatives of active methylene compounds, ethyl acetoacetate, and dimethyl acetylenedicarboxylate, the intermediates Vla-VIf were formed which on thermal cyclizations afforded other derivatives of 5H[l ]benzopyrano[3,4-b]pyridin-5-one (IVb-IVf). The nitration of IVa gave IVg.     

Properties of 4H-[1]benzopyrano[3,4-c]-[1,2,5]-selenodiazol-4-one

4H-[1]benzopyrano[3,4-c][1,2,5]selenodiazol-4-one has been synthesized by the reaction of 3,4-diaminocoumarin with selenous acid and its reaction with several nucleophiles (alkali, ammonia, amines, hydrazine hydrate) and its nitration have been studied. Using PMR spectroscopy, a comparative kinetic study of the opening of the lactone ring in 6,8-dinitro-4H-[1]benzopyrano[3,4-c][1,2,5]seleno- and thiadiazol-4-ones has been carried out.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 128–133, January, 1991.     

苯并吡喃[3,4-c]吡啶-5-酮类化合物的合成

以4-酮-3-甲酸甲酯哌啶盐酸盐为原料, 通过分子间环加成和N-烷基化反应, 合成了一系列潜在的多巴胺D₄受体配基苯并吡喃[3,4-c]吡啶-5-酮类化合物, 并用¹H NMR, IR, ESI-MS, 元素分析对其进行了表征.     

Synthesis of 3-(Dialkylamino)-4-halofuro[3,4-c]pyridin-1(3H)-ones

Russian Journal of Organic Chemistry - The reaction of 4-halo-3-hydroxyfuro[3,4-c]pyridin-1(3H)-ones with acyclic and alicyclic secondary amines in ethyl acetate afforded the corresponding...     

新型氮杂异香豆素化合物的合成

以4-氯烟酸和芳基乙腈为原料,经取代和环合反应合成了3个新型的氮杂异香豆素化合物（3a~3c）,收率32.1%~89.0%,其结构经¹H NMR, IR, ESI-MS和元素分析表征。用X-单晶衍射研究了3a的亚甲基衍生物（4a）的晶体结构。4a(CCDC: 935 919)属三斜晶系,空间群P ī, 晶胞参数a=6.881(2) , b=9.768(2) , c=11.809(2) , β=104.125(10)°, V=732.1³, Dc=1.331 mg·cm^-3 , Z=2, F(000)=308, μ=0.090 mm^-1。并对环合反应机理进行了研究。     

The synthesis of novel 1-hetarylmethylidene-4-sulfanylfuro-[3,4-c]pyridin-3(1H)-ones

Chemistry of Heterocyclic Compounds - 1-Hetarylmethylidene-4-sulfanylfuro[3,4-c]pyridin-3-ones were accessed from 4-thioxo-4,5-dihydrofuro[3,4-c]pyridin-3(1H)-one employing a condensation reaction...     

Some transformations of 3-amino-4-alkoxycarbonyl-6-hydroxy-2H-1-benzopyran-2-ones. The synthesis of [1] benzopyrano[3,4-d]-[1,3]oxazine and [1] benzopyrano[3,4-d]pyrimidine derivatives

Acylation of 4-alkoxycarbonyl-3-amino-6-hydroxy-2H-1-benzopyran-2-one derivatives 3 and 4 gave under mild conditions the O-substituted derivatives 5–10, N,O -disubstituted derivative 11 and N,N-disubstituted derivative 12 . The compound 4 was transformed with benzoyl chloride under more drastic conditions into 13 , a derivative of a new heterocyclic system 2-benzopyrano[3,4-d][1,3]oxazine. The derivatives of 1-benzopyrano-[3,4-d]pyrimidine 19 and 20 were prepared either from 3 and 4 through the corresponding N-heteroarylformamidines 14 and 15 and N-heteroarylformamide oximes 17 and 18 or by cyclization of thiourea derivative 20 .     

Synthesis of some isomeric 4,11-dihydro-5H-[1]benzoxocino[4,3-d] or [3,4-c]isoxazol-5-ones and isomeric 4,5,10,11-tetrahydrobenzo[5,6]-cycloocta[2,1-d] or [1,2-c]isoxazol-5-ones

The title compounds were prepared by acid-catalyzed cyclization of aryloxymethyl- or (2-arylethyl)-4-carboxymethylisoxazoles which in turn were synthesized from aryloxymethyl- or (2-arylethyl)isoxazole-4-carboxylic acids by Arndt-Eistert homologation.     

Synthesis of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones

By the condensation of 3,4-diaminothiocoumarins containing primary or secondary amino groups in position 4, with formic and acetic acids (or acetic anhydrides), a number of 1H-[1]benzothiopyrano[3,4-d]imidazol-4-ones and their 2-methyl derivatives have been synthesized; the latter have also been obtained from the corresponding 3-monoacetylamino-4-aminothiocoumarins. By the acetylation of 3-4-diaminothiocoumarins with tertiary amino groups in positions 4 their 3-diacetyl derivative has been obtained, and these, under the action of bases, have been converted into 3-N-acetyl derivatives. The structures of the compounds synthesized have been confirmed by IR, PMR, and mass spectroscopy.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 479–483, April, 1980.     

Synthesis of 2-Methyl-3-acetyl-5-oxo-5H-[1]benzopyrano[2,3-b]pyridine

For our synthetic work we needed the title compound. Literature survey revealed that 2-amino-4-oxo-4H-[1] benzopyran-3-carboxaldehyde (2-amino-3-formylchro-mone) can undergo condensation with diethyl malonate (or ethyl cyanoacetate) forming ethyl 2-hydroxy(or amino)-5-oxo-5H-[1]benzopyrano[2,3-b]pyridine-3-carboxylate¹.     

Investigations on furopyridines. 10. Synthesis of 4-N-substituted 1H-furo[3,4]pyridin-3-ones

2-Amino or 2-hydrazino derivatives of pyridine or pyridinopyrazole were obtained by amination or hydrazination of 2-chloro-3-cyano-4-methoxy-6-methylpyridine. Acid hydrolysis of these derivatives leads to heterocyclization with formation of 4-amino-1H-furo[3,4-c]pyridines or pyrazolo[3,4-b]pyridine. The possibility to synthesize 4-arylamino-1H-furo[3,4-c]-pyridines from 4-chloro-6-methyl-1H-furo[3,4-c]-pyridine has been shown.V. S. Pustovoit All-Russian Oil-Bearing Crops Research Institute, Krasnodar 350038, Russia. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 61–66, January, 1999.     

Mass spectrometric investigation of some [1]benzopyrano[3,4-c]pyrazole and [1]benzopyrano[4,3-d]isoxazole derivatives

The fragmentation behaviour of some [1]benzopyrano[3,4-c]pyrazole and [1]benzopyrano[4,3-d]isoxazole derivatives under electron impact is described.