3,4-二胺-1H-吡唑并[5,4-d]嘧啶的固相合成

用固相合成技术合成了吡唑并[5,4-d]嘧啶的一类衍生物8.以Merrifield树脂为原料,与化合物3反应得到树脂4.4经过还原胺化、取代、分子内亲核加成反应得到树脂7,再由三氟醋酸断裂得到化合物3,4-二胺-1H-吡唑并[5,4-d]嘧啶.     

Novel thieno[2,3-d]pyrimidines: their design, synthesis, crystal structure analysis and pharmacological evaluation

Novel thieno[2,3-d]pyrimidines containing a cyclohexane ring fused with a six- or five-membered heterocyclic moiety along with a benzylic nitrile were designed as potential inhibitors of PDE4. Expeditious synthesis of these compounds was carried out via a multi-step sequence consisting of a few key steps such as Gewald reaction, Dieckmann type cyclisation and Krapcho decarboxylation. This newly developed strategy involved construction of the thienopyrimidine ring followed by the cyclohexanone moiety and subsequently the fused heterocyclic ring. A number of thieno[2,3-d]pyrimidine based derivatives were synthesized using this method some of which showed promising PDE4B inhibitory properties. One of them was tested for PDE4D inhibition in vitro and dose dependent inhibition of TNF-α. A few selected molecules were docked into the PE4B protein the results of which showed good overall correlations to their observed PDE4B inhibitory properties in vitro. The crystal structure analysis of representative compounds along with hydrogen bonding patterns and molecular arrangement present within the molecule is described.     

Aminoethyl derivatives of 4-substituted pyrazolo[3,4-d]pyrimidines

New 3-aminoethyl derivatives of pyrazolo[3,4-d]pyrimidine were synthesized by reduction of 3-cyanomethylpyrazolo[3,4-d]pyrimidines with hydrazine hydrate in the presence of Raney nickel in alcohol.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 6, pp. 846–847, June, 1972.     

Synthesis and halogenation of allylthioethers of pyrazolo[3,4-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

The interaction of 6-allylthio-4-imino-1-methyl-3-methylthio-5-phenyl-1,5-dihydro-4H-pyrazolo[3,4-d]-pyrimidine with bromine leads to the formation of 8-bromomethyl-4-imino-1-methyl-3-methylthio-5-phenyl-4,5,7,8-tetrahydro-1H-pyrazolo[4,3-e][1,3]thiazolo[3,2-a] pyrimidinium tribromide. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 602–604. April, 2007.     

Pyrimidines

The reaction of methylenebisurea with 5-amino-1-R-pyrazoles and 3-ureido-1-phenylpyrazole gives 1- and 2-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines, respectively. The 1-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines are readily dehydrogenated to 1-R-6-hydroxypyrazolo[3,4-d]pyrimidines. The 2-R-6-oxo-4,5,6,7-tetrahydropyrazolo[3,4-d]pyrimidines could not be dehydrogenated.See [1] for communication XXXIV.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 12, pp. 1696–1699, December, 1972.     

3-Bromopyrazolo[3,4-d]pyrimidine 2'-deoxy-2'-fluoro-beta-D-arabinonucleosides: modified DNA constituents with an unusually rigid sugar N-conformation

The nucleobase anion glycosylation of 3-bromo-4-isopropoxy-1H-pyrazolo[3,4-d]pyrimidin-6-amine (6) with 3,5-di-O-benzoyl-2-deoxy-2-fluoro-alpha-d-arabinofuranosyl bromide (5) furnished the protected N(1)-beta-d-nucleosides 7 (60%) and 8 (ca. 2%) along with the N(2)-beta-d-regioisomer 9 (9%). Debenzoylation of compounds 7 and 9 yielded the nucleosides 10 (81%) and 11 (76%). Compound 10 was transformed to the 2'-deoxyguanosine derivative 1 [6-amino-3-bromo-1-(2-deoxy-2-fluoro-beta-d-arabinofuranosyl)-1H-pyrazolo[3,4-d]pyrimidin-4-one] (85% yield) and the purine-2,6-diamine analogue 2 [3-bromo-1-(2-deoxy-2-fluoro-beta-d-arabinofuranosyl)-1H-pyrazolo[3,4-d]pyrimidin-4, 6-diamine] (78%). Both nucleosides form more than 98% N-conformer population (P(N) ca. 358 degrees and psi(m) ca. 37 degrees ) in aqueous solution. Single-crystal X-ray analysis of 1 showed that the sugar moiety displays also the N-conformation [P = 347.3 degrees and psi(m) = 34.4 degrees ] in the solid state. The remarkable rigid N-conformation of the pyrazolo[3,4-d]pyrimidine 2'-deoxy-2'-fluoro-beta-d-arabinonucleosides 1 and 2 observed in solution is different from that of the parent purine 2'-deoxy-2'-fluoro-beta-d-arabinonucleosides 3 and 4, which are in equilibrium showing almost equal distribution of the N/S-conformers.     

Synthesis of alkyl thioethers of pyrazolo[3,4-<Emphasis Type="Italic">d</Emphasis>]pyrimidine

Reaction of 4-imino-1-methyl-5-phenyl-4,5,6,7-tetrahydro-1H-pyrazolo[3,4-d]pyrimidine-6-thione with unsaturated alkyl halides gives 4-imino-6-methallylthio(cinnamylthio, allylthio)-1-methyl-5-phenyl-4,5-dihydro-1H-pyrazolo[3,4-d]pyrimidines.     

Electrochemical oxidation of 4,5,6,7-tetrahydro-1H-pyrazolo[3,4-d] pyrimidine-4,6-dione (oxipurinol) at the pyrolytic graphite electrode

The electrochemical oxidation of 4,5,6,7-tetrahydro-1H-pyrazolo[3,4-d] pyrimidine-4,6-dione (oxipurinol) at the pyrolytic graphite electrode (PGE) has been studied. Oxipurinol exhibits up to three voltammetric oxidation peaks at the PGE between pH 1–12. The first pH-dependent peak (peak I_a) is proposed to be an initial, irreversible 2e-2H⁺ reaction to give 5,6-dihydro-4H-pyrazolo[3,4-d] pyrimidine-4,6-dione. This primary product further reacts by two routes. The major route, accounting for ca. 90% of the latter compound, involves a Michael addition of water followed by further electrochemical oxidation and hydrolysis to give 5,6-dihydro-5,6-dihydroxy-5-carboxy-6-diazenouracil. The minor route involves further electrochemical oxidation of 5,6-dihydro-4H-pyrazolo[3,4-d]-pyrimidine-4,6-dione in a 2e-2H⁺ reaction to give 4,5,6,7-tetrahydro-3H-pyrazolo[3,4-d]-pyrimidine-3,4,6-trione.Decomposition and, generally, additional electrochemical reactions of 5,6-dihydro-5,6-dihydroxy-5-carboxy-6-diazenouracil result in the formation of alloxan, parabanic acid, 6-diazo-isobarbituric acid and 5′-hydroxy-5-carboxy-6,6′-azouracil. The two latter compounds have never previously been reported. Decomposition of 4,5,6,7-tetrahydro-3H-pyrazolo[3,4-d]pyrimidine-3,4,6-trione results in formation of uracil-5-carboxylic acid.Detailed reaction schemes have been proposed to explain the observed electrochemistry and the formation of the observed products.     

Synthesis of 3-substituted 4-methylmercapto- and 4-aminopyrazolo-[3,4-d]pyrimidines and their ribosides

3-Cyano-4-methylmercaptopyrazolo[3,4-d]pyrimidine, fusion of which with 1,2,3,5-tetra-0-acetyl--D-ribofuranose gave its per-0-acetylated 1--D-ribofuranoside in 61% yield, was synthesized from 3,4-dicyano-5-aminopyrazole. 0-Deacetylation of the per-0-acetylated 1--D-ribofuranoside was carried out by the action of 1% HCl in methanol. New pyrazolo[3,4-d]pyrimidines were obtained by the reaction of 3-cyano-4-methylmercaptopyrazolo[3,4-d]pyrimidine and its 1-riboside, as well as 3-cyano-4-aminopyrazolo[3,4-d]pyrimidine, with a number of nucleophilic reagents. The cytotoxic activities of the compounds obtained were studied.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 253–258, February, 1984.     

Some reactions of 4-aminopyrazolo[3,4-d]pyrimidines

New 3-bromo and 1,4-diaminomethyl derivatives of 4-aminopyrazolo[3,4-d]pyrimidine were obtained by bromination and aminomethylation, respectively. 4-Bromopyrazolo[3,4-d]pyrimidines were synthesized for the first time by diazotization of 4-aminopyrazolo[3,4-d]pyrimidines.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 982–984, July, 1982.     

Binding affinity of substituted ureido‐benzenesulfonamide ligands to the carbonic anhydrase receptor: A theoretical study of enzyme inhibition

The binding properties of a series of benzenesulfonamide inhibitors (4‐substituted‐ureido‐benzenesulfonamides, UBSAs) of human carbonic anhydrase II (hCA II) enzyme with active site residues have been studied using a hybrid quantum mechanical/molecular mechanical (QM/MM) model. To account for the important docking interactions between the UBSAs ligand and hCA II enzyme, a molecular docking program AutoDock Vina is used. The molecular docking results obtained by AutoDock Vina revealed that the docked conformer has root mean square deviation value less than 1.50 Å compared to X‐ray crystal structures. The inhibitory activity of UBSA ligands against hCA II is found to be in good agreement with the experimental results. The thermodynamic parameters for inhibitor binding show that hydrogen bonding, hydrophilic, and hydrophobic interactions play a major role in explaining the diverse inhibitory range of these derivatives. Additionally, natural bond orbital analysis is performed to characterize the ligand–metal charge transfer stability. The insights gained from this study have great potential to design new hCA‐II inhibitor, 4‐[3‐(1‐p‐Tolyl‐4‐trifluoromethyl‐1H‐pyrazol‐3‐yl)‐ureido]‐benzenesulfonamide, which belongs to the family of UBSA inhibitors and shows similar type of inhibitor potency with hCA II. This work also reveals that a QM/MM model and molecular docking method are computationally feasible and accurate for studying substrate–protein inhibition. © 2013 Wiley Periodicals, Inc.     

Traceless solid-phase synthesis of bicyclic dihydropyrimidones using multidirectional cyclization cleavage

Solid-phase and solution-phase protocols for the synthesis of furo[3,4-d]pyrimidines, pyrrolo[3,4-d]pyrimidines, and pyrimido[4,5-d]pyridazines are reported. The multistep solid-phase sequence involves the initial high-speed, microwave-promoted acetoacetylation of hydroxymethylpolystyrene resin with methyl 4-chloroacetoacetate. The immobilized 4-chloroacetoacetate precursor was subsequently subjected to three-component Biginelli-type condensations employing urea and a variety of aromatic aldehydes. The resulting 6-chloromethyl-functionalized resin-bound dihydropyrimidones served as common chemical platforms for the generation of the desired heterobicyclic scaffolds using three different traceless cyclative cleavage strategies. The corresponding furo[3,4-d]pyrimidines were obtained by microwave flash heating in a rapid, thermally triggered, cyclative release. Treatment of the chloromethyl dihydropyrimidone intermediates with a variety of primary amines followed by high-temperature microwave heating furnished the anticipated pyrrolo[3,4-d]pyrimidine scaffolds via nucleophilic cyclative cleavage. In a similar way, reaction with monosubstituted hydrazines resulted in the formation of pyrimido[4,5-d]pyridazines. All compounds were obtained in moderate to good overall yields and purities.     

N-alkylation of substituted pyrazoles and pyrazolo[3,4-d]pyrimidines with dimethylformamide diethyl acetal or triethyl orthoformate

The N-alkylation of some substituted pyrazoles and pyrazolo[3,4-d]pyrimidines with dimethylformamide diethyl acetal or triethyl orthoformate has been examined. Dimethylformamide diethyl acetal is more effective as an alkylating agent than triethyl orthoformate. Alkylation of 3-methoxycarbonylpyrazole gives a mixture of N-1- and N-2-ethyl derivatives. Alkylation of pyrazolo[3,4-d]pyrimidines takes place at the 1-position of the pyrazole ring only. In the case of thio-derivatives of pyrazolo[3,4-d]pyrimidines, S-alkylation occurs in addition to N-alkylation.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 914–919, July, 1988.     

Synthesis of new pyrazolothiazole derivatives from 4-thiazolidinones

The synthesis of new 2,3,5,6-aryl substituted tetrahydro-2H-pyrazolo[3,4-d]- thiazoles 4a-j as potential biologically active compounds by the cyclocondensation of phenyl hydrazine with new 5-arylidene derivatives 2a-j of 2,3-disubstituted-1,3- thiazolidin-4-ones 1a-e is reported.     

Synthesis of pyrazolone derivatives—XXI : On the reduction of 1-methyl-2-phenyl-1,2,3,10-tetrahydro-4H-pyrazolo[3,4-c][1] benzothiepin-3,4-dione with sodium borohydride

The selective reduction of α,β-unsaturated ketones and CC double bonds of pyrazolo[3,4-c][1]benzothiepins with sodium borohydride was studied. The reduction of 1-methyl-2-phenyl-1,2,3,10-tetrahydro-4H-pyrazolo[3,4-c][1]benzot (1) with sodium borohydride in refluxing methanol gave 1-methyl-2-phenyl-1,2,3,10-tetrahydro-4H-pyrazolo[3,4-c][1]benzothiepin-3-one (2). The mechanism of this unusual reaction in which the heterocyclic ketone was reduced to the corresponding methylene grouping with such a reagent was elucidated by the isolation of the following intermediates: 1-methyl-2-phenyl-1,2,3,3a, 10, 10a-hexahydro-4H-pyrazolo[3,4-c][1]benzothiepin-3,4-dione (6) and 1-methyl-2-phenyl-1,2,3,3a,10,10a-hexahydro-4H-pyrazolo[3,4-c][1]benzothiepin-3-one (4).     

Synthesis of Some New Biologically Active Sulfur Compounds Containing Pyrazolo[3,4-d] pyrimidine Moiety

A novel series of the pyrazolo[3,4-d]pyrimidines having biologically active sulfur moieties 3-20 were prepared via reaction of 4-mercapto-1-phenyl-1 H -pyrazolo[3,4-d]pyrimidine 3 with different reagents. Identification of the new compounds was established by elemental analyses, IR, 1 H-NMR, and mass spectral data. Some of the obtained compounds showed the interesting antimicrobial activity comparable to antibiotic chloramphenicol as standard antibacterial agent and Terbinafin as a standard antifungal agent.     

Synthesis and properties of 2-substituted 1-aryl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines

Cyclization of 2-(N-acetyl-N-arylamino)nicotinonitriles in the presence of dry HCl gave 1-aryl-2-methyl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines. It was shown that they are acylated by acetic anhydride, aroyl chlorides, and phenyl isocyanate at the methyl group and that with benzaldehyde they give styryl derivatives. It was determined by UV, IR, and NMR spectra that 2-acetonyl, 2-phenacyl, and 2-(N-phenylcarbamoylmethyl) derivatives of 1-aryl-4-oxo-1,4-dihydropyrido[2,3-d]pyrimidines exist in enaminocarbonyl and imino enol forms with strong chelate-type intramolecular hydrogen bonding.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1397–1401, October, 1991.     

Synthesis and halogenation of propargyl pyrazolo-[3,4-d]pyrimidine thioether

The reaction of 4-imino-1-methyl-5-phenyl-6-propargylthio-1,5-dihydro-4H-pyrazolo[3,4-d]pyrimidine with halogens leads to the formation of (Z)-8-halomethylene-4-imino-1-methyl-5-phenyl-4,5,7,8-tetrahydro-1H-pyrazolo[4,3-e][1,3]thiazolo[3,2-a]pyrimidinium trihalide. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 1085–1088, July, 2008.     

Synthesis and Antiproliferative Activity of Some Newly Synthesized Pyrazolopyridine Derivatives

Russian Journal of General Chemistry - A series of pyrazolopyridine derivatives is synthesized from emyl-4-amino-6-memyl-1-(mphtha[1,2-d]-[1,3]tmazol-2-yl)-1H-pyrazolo[3,4-b]pyridine-5-carboxylate...     

Synthesis and Antibacterial Evaluation of New Pyrazolo[3,4-d]pyrimidines Kinase Inhibitors

Pyrazolo[3,4-d]pyrimidines represent an important class of heterocyclic compounds well-known for their anticancer activity exerted by the inhibition of eukaryotic protein kinases. Recently, pyrazolo[3,4-d]pyrimidines have become increasingly attractive for their potential antimicrobial properties. Here, we explored the activity of a library of in-house pyrazolo[3,4-d]pyrimidines, targeting human protein kinases, against Staphylococcus aureus and Escherichia coli and their interaction with ampicillin and kanamycin, representing important classes of clinically used antibiotics. Our results represent a first step towards the potential application of dual active pyrazolo[3,4-d]pyrimidine kinase inhibitors in the prevention and treatment of bacterial infections in cancer patients.