Arene imine derivatives of nitrogen heterocycles: 1a,9b-dihydrobenz[h]-azirino[f]quinoline, 1a,9b-dihydrobenz[f]azirino[h]quinoline and 1a,9b-dihydroazirino[f][1,10]phenanthroline

The syntheses of the K-imine derivatives of benzo[h]quinoline ( 1 ), benzo[f]quinoline ( 2 ) and 1,10-phenanthroline ( 3 ) are described. The parent nitrogen heterocycles were oxidized with sodium hypochlorite to the corresponding K-oxides, 4, 6 and 8 , which in turn were reacted with sodium azide. The resulting azido alcohols were then cyclized with triethyl phosphite to the title compounds 5, 7 and 9 . The oxirane ring cleavage in benzo[h]quinoline 5,6-oxide ( 4 ) and in benzo[f]quinoline 5,6-oxide ( 6 ) by sodium azide proceeded by the predicted regioselectivity: 4 gave trans-5-azido-5,6-dihydro-6-benzo[h]quinolinol ( 11 ) and trans-6-azido-5,6-dihydro-5-benzo[h]quinolinol ( 10 ) as the major and minor products respectively, and 6 yielded solely trans-6-azido-5,6-dihydro-5-benzo[f]quinolinol ( 12 ). The latter compound proved by X-ray analysis to crystallize as a hydrogen bonded dimer.     

Base-mediated one-pot synthesis of 3,4,5,6-tetrahydro-4-substituted benzo[h]quinazoline-2(1H)-thione derivatives and evaluation of their antioxidant activity

One-pot three-component Beginelli-like reactions of a ketone 1, an aryl aldehyde 2, and thiourea 3 in the presence of sodium hydroxide are described. In this reaction, 3,4,5,6-tertrahydro-4-substituted quinazoline-2(1H)-thione derivatives 4a–h were obtained in good yields (73–85%). The compound 4a has been characterized by single crystal X-ray analysis. All the synthesized compounds 4a–h and 5a–b were screened for their in vitro antioxidant activity. Compounds 4c, 4e, and 4h have exhibited an excellent than the standard ascorbic acid. Compounds 4d, 4f, and 4g have also shown good activity. Remaining compounds show moderate antioxidant activity.     

Condensation reactions of indole with acetophenones affording mixtures of 3,3-(1-phenylethane-1,1-diyl)bis(1H-indoles) and 1,2,3,4-tetrahydro-3-(1H-indol-3-yl)-1-methyl-1,3-diphenylcyclopent[b]indoles

Condensation of indole 1a with eight acetophenones 8a–h in ethanolic HCl afforded the corresponding mixtures of condensation products: 3,3-(1-phenylethane-1,1-diyl)bis(1H-indoles) 11a–h (2:1 condensation of indole:acetophenone, –H₂O) and diastereomers of substituted 1,2,3,4-tetrahydro-3-(1H-indol-3-yl)-1-methyl-1,3-diphenylcyclopent[b]indoles 12a–h and 13a–h (2:2 condensation of indole:acetophenone, –2H₂O). Each mixture was analyzed by ¹H NMR. The use of substituted electron-withdrawing acetophenones favored formation of 2:1 condensation products, whereas the use of substituted electron-donating acetophenones favored formation of 2:2 condensation products. Increased reaction temperature gave higher 2:2 condensation yields, but temperatures above 40?°C were unfavorable, giving complex, tarry mixtures.     

New Ionic Liquid Compounds Based on Tantalum Pentachloride TaCl5: Synthesis,Structural, and Spectroscopic Elucidation of the (μ‐Oxido)‐Chloridotantalates(V) [BMPy][TaCl6], [BMPy]4[(TaCl6)2(Ta2OCl10)], and [EMIm]2[Ta2OCl10]

1‐Butyl‐4‐methylpyridinium hexachloridotantalate(V), [BMPy][TaCl₆] ( 1 ), tetrakis(1‐butyl‐4‐methylpyridinium) bis(hexachloridotantalate(V) (μ‐oxido)‐decachloridotantalate(V), [BMPy]₄[(TaCl₆)₂(Ta₂OCl₁₀)] ( 2 ), and bis(1‐ethyl‐3‐methylimidazolium)‐(μ‐oxido)‐decachloridoditantalate(V), [EMIm]₂[Ta₂OCl₁₀] ( 3 ) were synthesized and characterized by single‐crystal X‐ray diffraction and vibrational spectroscopy. Compounds 1 and 3 crystallize in the monoclinic space group P2₁/c (no. 14), whereas compound 2 crystallizes in the triclinic space group P (no. 2). All compounds are built up by the mentioned bulky organic cations and octahedral [TaCl₆]^– respective linear [Ta₂OCl₁₀]^2– anions. Coulomb interactions are dominant between the ionic species. FT‐IR and FT‐Raman spectra were recorded and interpreted, especially with respect to the inorganic species [TaCl₆]^– (O_h) and [Ta₂OCl₁₀]^2– (C_i symmetry, approximately D_4h). The melting temperatures of compounds 1 – 3 are given.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 3 . 12-Methylbenzo[h][1]benzothieno[2,3-c][1,6]naphthyridine

The synthesis of the 12-methyl derivative of a novel heterocyclic ring system, namely benzo[h][1]benzothieno[2,3-c][1,6]naphthyridine ( 8 ) was prepared by photocyclization of 3-chloro-N-(2′-methyl-4′-quinolyl)benzo-[6]thiophene-2-carboxamide ( 5 ) to 12-methylbenzo[h][1]benzothieno[2,3-c][1,6]naphthyridin-6(5H)-one ( 6 ). Chlorination of 6 afforded 6-chloro-12-methylbenzo[h][1]benzothieno[2,3-c][1,6]naphthyridine ( 7 ) which upon dechlorination provided the novel title compound 8 .     

Synthesis of a series of diaminobenzo[f]- and diaminobenzo[h]pyrimido[4,5-b]quinolines as 5-deaza tetracyclic nonclassical antifolates

A series of diaminobenzo[f]- and diaminobenzo[h]pyrimido[4,5-b]quinolines 1–11 were designed as 5-deaza tetracyclic nonclassical, lipophilic antifolates. The compounds were designed as conformationally semi-rigid and rigid analogs of 2,4-diamino-6-phenyl- 12 and 2,4-diamino-7-phenylpyrido[2,3-d]pyrimidines 13 and 14 . The target compounds were synthesized by cyclocondensation of chlorovinyl aldehydes obtained from appropriately substituted 1- or 2-tetralone, with 2,4,6-friaminopyrimidine. Compounds 1–11 were evaluated as inhibitors of P. carinii and T. gondii dihydrofolate reductases. These pathogens cause fatal opportunistic infections in AIDS patients. In addition, the selectivity of these agents was evaluated using rat liver dihydrofolate reductase as the mammalian source. In general the benzo[f]pyrimido[4,5-b]quinolines 1–5 were more potent than the corresponding benzo[h]pyrimido[4,5-b]quinoline analogues 6–11 against P. carinii and rat liver dihydrofolate reductase and were equipotent against T. gondii dihydrofolate reductase. Compounds 6–11 were moderately selective towards T. gondii dihydrofolate reductase with IC₅₀S in the 10⁻⁷ M range. In contrast analogues 1–5 lacked selectivity against P. carinii or T. gondii dihydrofolate reductase and were, in general, potent inhibitors of rat liver dihydrofolate reductase with IC₅₀S in the 10⁻⁸ M range. Analogues 1 and 4 were evaluated against a series of tumor cell lines in vitro and were found to have moderate antitumor activity (IC50 10⁻⁶ M). The structure activity/selectivity relationships suggest that benzo[f]pyrimido analogues 1–5 with the phenyl ring substitution in the “upper” portion of the tetracyclic ring are better accommodated within the rat liver (mammalian) dihydrofolate reductase and P. carinii dihydrofolate reductase active sites compared to the benzo[h]pyrimido analogues 6–11 which have the phenyl ring substitution in the “lower” portion of the tetracyclic ring. In contrast T. gondii dihydrofolate reductase does not discriminate between the isomers and binds to both series of compounds with similar affinities.     

Inhibitors of platelet aggregation. 4. [1,2,5]Thiadiazolo[3,4-c]acridines, 7,8,9,10-Tetrahydro[1,2,5] thiadiazolo[3,4-c]acridities,and 8,9-Dihydro-7H-cyclopenta[b][1,2,5] thiadiazolo[3,4-H]quinolines

The condensation of 4-amino-2,1,3-benzothiadiazole (IV) with diphenyliodonium-2-earboxylate gave N-(2,1,3-benzothiadiazoI-4-yl)anthranilic acid (V) (28%), which was cyclized with phosphorus oxychloride to 6-chloro[1,2,5]thiadiazolo[3,4-c]acridine (VI) (84%). Treatment of VI with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol afforded 6-[ [3-(dimethylamino)-propyl]thio] [1,2,5]thiadiazolo[3,4-c]acridine (VII) (65%). The reaction of IV with a mixture of methyl and ethyl 2-oxocyclohexanecarboxylate gave the adduct, which was ring closed in Dowtherm to 7,9,10,1 1-tetrahydro[1,2,5] thiadiazolo[3,4-c]acridin-6(8H)one (VIII) (70%). Chlorination of VIII with phosphorus oxychloride gave 6-chloro-7,8,9,10-tetrahydro[1,2,5]thiadiazolo[3,4-c]acridine (IX) (84%), which was condensed with 3-(dimethylamino)-1-propanethiol hydrochloride in phenol yielding 6-[ [3-(dimethylamino)propyl]thio]-7,8,9,10-tetrahydrof 1,2,5]-thiadiazolo[3,4-c]acridine (X) (27%). 6-[ [3(1)imethylamino)propyl]thio]-8,9-dihydro-7H-cyclopenta[b] [1,2,5]thiadiazolo[3,4-h]quinoline (XIII) (25%) was prepared similarly from IV and a mixture of methyl and ethyl 2-oxocyclopentanecarboxylate via 7,8,9,10-tetrahydro-6H-cyclopenta[b][1,2,5]thiadiazolo[3,4-h]quinolin-6-one (XI) (85%) and 6-chloro-8,9-dihydro-7H-cyclopenta[b][1,2,5]thiadiazolof3,4-h]quinoline (XII) (56%). The effects of compounds VII-XIII as inhibitors of platelet aggregation are discussed.     

One-pot synthesis of novel 1,2,3-triazole-pyrimido[4,5-c]isoquinoline hybrids and evaluation of their antioxidant activity

A series of novel pyrimido[4,5-c]isoquinolines (3a–3h) and 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinolines (4a–4h) were synthesized in good to excellent yields in the one-pot method. The reaction of 6-amino-1,3-dimethyluracil with different 2-iodo benzoyl chlorides using Pd catalyst in dimethylformamide afforded corresponding pyrimido[4,5-c]isoquinolines (3a–3h). One-pot reaction of pyrimido[4,5-c]isoquinolines with propargyl bromide and benzyl azide in THF at room temperature furnished 1,2,3-triazole-coupled pyrimido[4,5-c]isoquinoline (4a–4h). In vitro antioxidant activity examination revealed that compounds 4d and 4c found to exhibit potent antioxidant activity as compared to the standard drug Trolox with IC₅₀ values 6.02?±?0.6 and 12.18?±?0.9?µM, respectively.     

Synthese und spektroskopische Charakterisierung von [Rh(SeCN)6]3– und trans‐[Rh(CN)2(SeCN)4]3–, Kristallstruktur von (Me4N)3[Rh(SeCN)6]

Synthesis and Spectroscopic Characterization of [Rh(SeCN)₆]^3– and trans ‐[Rh(CN)₂(SeCN)₄]^3–, Crystal Structure of (Me₄N)₃[Rh(SeCN)₆] Treatment of RhCl₃ with KSeCN in acetone yields a mixture of selenocyanato‐rhodates(III), from which [Rh(SeCN)₆]^3– and trans‐[Rh(CN)₂(SeCN)₄]^3– have been isolated by ion exchange chromatography on diethylaminoethyl cellulose. The X‐ray structure determination on a single crystal of (Me₄N)₃[Rh(SeCN)₆] (trigonal, space group R3, a = 14.997(2), c = 24.437(3) Å, Z = 6) reveals, that the compound crystallizes isotypically to (Me₄N)₃[Ir(SCN)₆]. The exclusively via Se coordinated selenocyanato ligands are bonded with the average Rh–Se distance of 2.490 Å and the Rh–Se–C angle of 104.6°. In the low temperature IR and Raman spectra the metal ligand stretching modes ν(RhSe) of (n‐Bu₄N)₃[Rh(SeCN)₆] ( 1 ) and trans‐(n‐Bu₄N)₃[Rh(CN)₂(SeCN)₄] ( 2 ) are in the range of 170–250 cm^–1. In 2 ν_as(CRhC) is observed at 479 cm^–1. The vibrational spectra are assigned by normal coordinate analysis based on the molecular parameters of the X‐ray determination. The valence force constants are f_d(RhSe) = 1.08 ( 1 ), 1.10 ( 2 ) and f_d(RhC) = 3.14 mdyn/Å ( 2 ). f_d(RhS) = 1.32 mdyn/Å is determined for [Rh(SCN)₆]^3–, which has not been calculated so far. The ¹⁰³Rh NMR resonances are 2287 ( 1 ), 1680 ppm ( 2 ) and the ⁷⁷Se NMR resonances are –32.7 ( 1 ) and –110.7 ppm ( 2 ). The Rh–C bonding of the cyano ligand in 2 is confirmed by a dublett in the ¹³C NMR spectrum at 136.3 ppm.     

Quantum chemical study of the structure of bicyclo[2.2.0]hex-1(4)-ene and its dimers

The RHF, B3LYP, and PBE0/6-311G** quantum chemical methods are used to determine the point symmetry group and the equilibrium structure of bicyclo[2.2.0]hex-1(4)-ene (I, D _2h ), its two stable dimers (tricyclo[4.2.2.2^2,5]dodeca-1.5-diene (II, D _2h ) and 2,5-dimethylenetricyclo[4.2.2.0^1,6]decane (III, C ₂)), and pentacyclo [4.2.2.2^2,5]dodecane (IV, D ₂) that is a hypothetical intermediate in the dimerization reaction of the molecules of I. The relation of total energies is obtained with regard to zero-point vibrations: E(III) < E(II) ≪ E(IV) ≪ 2E(I).     

Kristallstrukturen,Schwingungsspektren und Normalkoordinatenanalyse von (n‐Bu4N)2[Os(NCS)6] und (n‐Bu4N)3[Os(NCS)6]

Crystal Structure, Vibrational Spectra, and Normal Coordinate Analysis of ( n ‐Bu₄N)₂[Os(NCS)₆] and ( n ‐Bu₄N)₃[Os(NCS)₆] By tempering the solid mixture of the linkage isomers (n‐Bu₄N)₃[Os(NCS)_n(SCN)_6–n] n = 0–5 for a longer time at temperatures increasing from 60 to 140 °C the homoleptic (n‐Bu₄N)₃[Os(NCS)₆] is formed, which on oxidation with (NH₄)₂[Ce(NO₃)₆] in acetone yields the corresponding Os^IV complex (n‐Bu₄N)₂[Os(NCS)₆]. X‐ray structure determinations on single crystals of (n‐Bu₄N)₂[Os(NCS)₆] (1) (triclinic, space group P 1, a = 12.596(5), b = 12.666(5), c = 16.026(5) Å, α = 88.063(5), β = 80.439(5), γ = 88.637(5)°, Z = 2) and (n‐Bu₄N)₃[Os(NCS)₆] ( 2 ) (cubic, space group Pa 3, a = 24.349(4) Å, Z = 8) have been performed. The nearly linear thiocyanate groups are coordinated with Os–N–C angles of 172.3–177.7°. Based on the molecular parameters of the X‐ray determinations the IR and Raman spectra are assigned by normal coordinate analysis. The valence force constant f_d(OsN) is 2.3 ( 1 ) and 2.10 mdyn/Å ( 2 ).     

Polycyclic N-hetero compounds. XIX. Synthesis of novel meso-ionic benz[h]imidazo[1,2-c]quinazoline and benzo[h]pyrrolo[1′,2′:3,4]imidazo[1,2-c]quinazoline derivatives

Benz[h]imidazo[1,2-c]quinazolinium-l-olate (5) and benzo[h]pyrrolo[1′,2′:3,4]imidazo[1,2-c]quinazolinium-8-olate (9) having novel meso-ionic ring systems were synthesized by the reaction of N-(5,6-dihydrobenzo[h]-quinazolin-4-yl)amino acids with acetic anhydride.     

Darstellung und Kristallstrukturen von (Ph3PNPPh3)2[Re2Br10] und (Ph4P)[Re2Br9]

Synthesis and Crystal Structures of (Ph₃PNPPh₃)₂[Re₂Br₁₀] and (Ph₄P)[Re₂Br₉] Depending on the molar ratio by reaction of [n-Bu₄N]₂[ReBr₆] with the Lewis acid BBr₃ in dichloromethane the bioctahedral complexes [n-Bu₄N]₂[Re₂Br₁₀] and [n-Bu₄N][Re₂Br₉] are formed. The X-ray structure determination on (Ph₃PNPPh₃)₂[Re₂Br₁₀] (monoclinic, space group C 2/c, a = 20.007(4), b = 15.456(5), c = 24.695(4) Å, β = 107.53(2)°, Z = 4) reveals a centrosymmetric edge-sharing complex anion with approximate D_2h symmetry and mean terminal and bridging Re–Br bond lengths of 2.453 (equatorial), 2.482 (axial) and 2.591 Å, respectively, and a Re–Re distance of 3.880 Å. (Ph₄P)[Re₂Br₉] (triclinic, space group P 1, a = 11.062(2), b = 12.430(3), c = 13.163(5) Å, α = 72.94(2), β = 68.47(2), γ = 82.09(2)°, Z = 2) contains a confacial bioctahedral anion with nearly D_3h symmetry and mean terminal and bridging Re–Br distances of 2.460 and 2.536 Å, respectively, and a Re–Re distance of 2.780 Å.     

Die Synthese von Azaisomeren des Triesters von PQQ: 3H-Pyrrolo[3,2-f]-, 1H-Pyrrolo[3,2-h]- und 7H-Pyrrolo[2,3-h]chinolinchinon-Derivate

The Synthesis of Azaisomers of the Triester of PQQ: 3H-Pyrrolo[3,2-f]-, 1H-Pyrrolo[3,2-h]-, and 7H-Pyrrolo[2,3-h]quinolinequinone Derivatives We describe here the synthesis of the title compounds 3–5 , starting from highly substituted aminoindoles. The annelated pyridine rings were built up in each case with dimethyl 4-oxoglutaconate according to Corey's procedure. All three o-quinone derivatives 3–5 are stable compounds, comparable to PQQ-triester. The azaisomers vary in biological activity from practically inactive to strong inhibition of the α-amidating enzyme or the ornithin decarboxylase.     

Further studies on heterocyclic arene imines. Preparation of 1a,9b-dihydroazirino[f][1,7]phenanthroline, 3b,4a-dihydroazirino-[2,3]phenaleno[1,9-g,h]quinoline and 1a,13b-dihydrodibenzo[1,2:6,7]phenazino[1,2-b]azirine

The syntheses of the K-imine derivatives of 1,7-phenanthroline, phenaleno[1,9-g,h]quinoline, and dibenzo[a,h]phenazine are described. The parent heterocyclic compounds 4, 9 and 14 were oxidized to the corresponding K-oxides, 5, 10 and 15 , which in turn were reacted with sodium azide in aqueous acetone. The resulting trans-azido alcohols were then cyclized with tributylphosphine to the title compounds 6, 11 and 16 .     

Au(I)-Catalyzed 6-endo-dig Cyclizations of Aromatic 1,5-Enynes to 2-(Naphthalen-2-yl)anilines Leading to Divergent Syntheses of Benzo[α]carbazole,Benzo[c,h]cinnoline and Dibenzo[i]phenanthridine Derivatives

A gold(I)-catalyzed 6-endo-dig cyclization of aromatic 1,5-enynes was developed to synthesize 2-(naphthalen-2-yl)anilines. The functional group tolerance of this cyclization was examined systematically and a possible mechanism was proposed. The derivatization of 2-(naphthalen-2-yl)aniline was carried out to facile access to benzo[α]carbazole, benzo[c,h]cinnoline and dibenzo[i]phenanthridine derivatives in a divergent way.     

Die Struktur der Hydrate von Co3[Co(CN)6]2 und Cd3[Co(CN)6]2

The crystal structures of Co₃[Co(CN)₆]₂, 12 H₂O (a, = 10.210 ± 0.005 Å) and Cd₃[Co(CN)₆]₂, 12 H₂O (a = 10.590 ± 0.005 Å) have been determined by X-ray powder methods. According to the measured density the unit cell contains 1 1/3 formula units with 4 Co²⁺ (Cd²⁺) in 4a, 2 2/3 Co³⁺ in 4b, 16 C and 16 N in 24e, 8 H₂O_I near 24e, (96k) and 8 H₂O_II near 8 _c (192 l). Structure factor calculations based on the space group O_h⁵ - F m 3 m lead to the following final values of the reliability index R: 0.038 (Co₃[Co(CN)₆]₂, 12 H₂O) and 0.037 (Cd₃[Co(CN)₆]₂, 12 H₂O). The interatomic distances for the cobaltous compound (in parentheses for the cadmium compound) are: Co³⁺-C: 1.88 Å (1.89); C-N: 1.15 Å (1.17); Co²⁺-N: 2.08 Å (2.24); Co²⁺-O_I: 2.10 Å (2.27); shortest O_I-H-O_II-bonds: 2.89 Å (2.82). Co³⁺ is octahedrally coordinated by six carbon atoms, the divalent metal ion by four nitrogen atoms and two water molecules. The two different metal ions are connected by M²⁺-N-C-Co³-bonds to a threedimensional network. The infrared and electronic spectra are shown to be in agreement with the results of the structure analyses of these compounds. The observed positions of the OH-stretching vibrations lead to a hydrogenbond-length of 2.8–2.95 Å.     

The synthesis of novel polycyclic heterocyclic ring systems via photocyclization. 7. [1]Benzothieno[2,3-c]naphtho[2,1-h]quinoline and [1]benzothieno[2,3-c]naphtho[2,1-h][1,2,4]triazolo[4,3-a]quinoline

The synthesis of two novel polycyclic heterocyclic ring systems via photocyclization is described. These are [1]benzothieno[2,3-c]naphtho[2,1-h]quinoline and [1]benzothieno[2,3-c]naphtho[2,1-h][1,2,4]triazolo[4,3-α]-quinoline. In the ¹H nmr spectrum the proton at position 6 is strongly deshielded in the first ring system while the proton at position 6 in the second ring system is shifted considerably upfield while the proton at position 8 in the second ring system is the most deshielded proton in that ring system. The bay regions in both ring systems are severely congested.     

Synthesis, Characterization and Crystal Structure of （Z）-1-[2-（Triarylstannyl）vinyl]-1-indanols and Their Arylhalostannyl Derivatives

(Z)-1-[2-(Tri-o-tolylstannyl)vinyl]-1-indanol (1) and (Z)-1-[2-(tri-p-tolylstannyl)vinyl]-l-indanol (2) were synthesized by the addition reaction of 1-ethynylindanol with tri-o-tolyltin and tri-p-tolyltin hydride. The aryl groups in compound 1 and 2 were substituted by Br2 or I2 to yield monohalide derivatives (3-6). The compounds 1-6 were characterized by elemental analysis, ^1H NMR and FT-IR spectroscopy. The crystal structures of 1, 2 and 4 have been determined by single crystal X-ray diffraction analysis. The Sn atom in 1 and 2 exhibits a tetrahedral geometry distorted towards trigonal bipyramid due to a weak intramolecular interaction between Sn and the hydroxyl O atoms [0.2839(4) nm and 0.2744(5) nm], while the Sn atom in 4 adopts a trigonal bipyramidal geometry with a significant O→Sn(1) interaction [0.2552(5) nm].     

One-pot,three-component synthesis of polyfunctionalized benzo[h]pyrazolo[3,4-b][1,6]naphthyridine and benzo[g]pyrazolo[3,4-b]quinoline derivatives in the presence of silver nanoparticles (AgNPs)

An efficient and straightforward protocol for one-pot, three-component reaction of aryl glyoxal monohydrates 1a-h , 5-amino-1-aryl-3-methylpyrazoles 2a , b and 4-hydroxyquinoline-2(1H)-one ( 3 ) or 2-hydroxy-1,4-naphthoquinone ( 4 ) using silver nanoparticles (AgNPs) as a high performance nanocatalyst in H₂O/EtOH at 60°C afforded the corresponding polyfunctionalized benzo[h]pyrazolo[3,4-b][1,6]naphthyridines 5a-h and benzo[g]pyrazolo[3,4-b]quinolines 6a-i , respectively. Excellent catalytic activity, high yields, employing green media and green nanocatalyst, cost-effective and simple procedure are some notable advantages of using AgNPs as a noble metal nanocatalyst in this synthetic strategy. The structures of fused heterocycles were confirmed by their Fourier transform infrared, proton nuclear magnetic resonance (¹H-NMR), and ¹³C-NMR spectral data and microanalysis.