- Hydrogenation/dehydrogenation of N-heterocycles catalyzed by ruthenium complexes based on multimodal proton-responsive CNN(H) pincer ligands
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Ru complexes based on lutidine-derived pincer CNN(H) ligands having secondary amine side donors are efficient precatalysts in the hydrogenation and dehydrogenation of N-heterocycles. Reaction of a Ru-CNN(H) complex with an excess of base produces the formation of a Ru(0) derivative, which is observed under catalytic conditions.
- álvarez, Eleuterio,Hernández-Juárez, Martín,López-Serrano, Joaquín,Paneque, Margarita,Rendón, Nuria,Sánchez, Práxedes,Santos, Laura L.,Suárez, Andrés
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supporting information
p. 9583 - 9587
(2020/07/30)
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- Cu@U-g-C3N4 Catalyzed Cyclization of o-Phenylenediamines for the Synthesis of Benzimidazoles by Using CO2 and Dimethylamine Borane as a Hydrogen Source
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Abstract: This work reports a green and sustainable route for the synthesis of benzimidazoles via C–N bond formation using carbon dioxide (CO2) as a C1 carbon source. In this work, Cu@U-g-C3N4 catalyst was prepared from urea derived porous graphitic carbon?nitride (U-g-C3N4) and CuCl2 and characterized by FT-IR, XRD, XPS, SEM, TPD etc. The Cu@U-g-C3N4 as a heterogeneous recyclable catalyst has been employed first time for the cyclization of o-phenylenediamines (OPD) with CO2 to benzimidazoles using dimethylamine borane (DMAB). The proposed protocol becomes sustainable and efficient due to the use of propylene carbonate/water as a suitable biodegradable, economical and environmentally benign solvent system. The proposed catalytic system showed a wide range of substrate scope for the synthesis of benzimidazoles in good to excellent yields. Graphical Abstract: [Figure not available: see fulltext.]
- Phatake, Vishal V.,Bhanage, Bhalchandra M.
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p. 347 - 359
(2018/11/23)
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- Gold(0) catalyzed dehydrogenation of N-heterocycles
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Gold nanoclusters are good catalyst precursors for the catalytic dehydrogenation of indolines, tetrahydroquinazolines, and related N-heterocycles. The catalytically active species is presumably Au(0) nanoparticles.
- Kumaran, Elumalai,Leong, Weng Kee
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p. 3958 - 3960
(2018/10/02)
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- Oxalic/malonic acids as carbon building blocks for benzazole, quinazoline and quinazolinone synthesis
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An oxidant, base and metal free methodology has been developed for the synthesis of various 2-substituted and non-substituted benzazoles, quinazolines and quinazolinones using oxalic/malonic acids as an in situ carbon source. This methodology is applicable for a wide range of substituted o-phenylenediamine, o-aminothiophenol, o-aminophenol and o-aminobenzamide containing various functional groups and provides good to excellent yields of the corresponding product. Furthermore an easy workup procedure, high yield and easy isolation of products are key features of this methodology. The developed protocol is also applicable for the gram scale synthesis of benzimidazoles.
- Sharma, Saurabh,Bhattacherjee, Dhananjay,Das, Pralay
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supporting information
p. 1337 - 1342
(2018/03/06)
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- Divergent Synthesis of Quinazolines Using Organocatalytic Domino Strategies under Aerobic Conditions
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An easy and efficient organocatalytic approach to the synthesis of 2-substituted quinazolines is described based on the reaction between 2-aminobenzylamines and aldehydes or alcohols or amines. Three organocatalytic platforms were investigated, using 3-nitropyridine, pyridine N-oxide, and vitamin B3. Having established the new catalytic systems, the tandem transformations of 2-aminobenzylamines to give substituted quinazolines were achieved in excellent yields and with a broad substrate scope, with no formation of toxic side-products. The investigated conditions are not restricted to the use of aldehydes; the protocol also works well with alcohols or amines as substrates. These are oxidized in situ to the corresponding aldehydes to achieve the successful transformation. A mechanistic proposal has been drawn up based on control experiments. We found that under aerobic conditions, catalytic amounts of H2O2 can be generated; this plays a key role in the efficacy of the described approach. The green chemistry metrics of the developed method are also presented. The E factor of 8.18 mg/1 mg demonstrates that the reported method is an excellent complement to previous protocols.
- Gujjarappa, Raghuram,Maity, Suvik K.,Hazra, Chinmoy K.,Vodnala, Nagaraju,Dhiman, Shiv,Kumar, Anil,Beifuss, Uwe,Malakar, Chandi C.
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p. 4628 - 4638
(2018/09/13)
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- The cascade synthesis of quinazolinones and quinazolines using an α-MnO2 catalyst and tert-butyl hydroperoxide (TBHP) as an oxidant
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Heterogeneously catalyzed synthesis of quinazolinones or quinazolines is reported in this study. An α-MnO2 catalyst is found to be highly active and selective in the oxidative cyclization of anthranilamides or aminobenzylamines with alcohols using TBHP as an oxidant. This protocol exhibits a broad substrate scope, and is operationally simple without an additive.
- Zhang, Zhe,Wang, Min,Zhang, Chaofeng,Zhang, Zhixin,Lu, Jianmin,Wang, Feng
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supporting information
p. 9205 - 9207
(2015/06/02)
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- NaBH4-TMEDA and a palladium catalyst as efficient regio- and chemoselective system for the hydrodehalogenation of halogenated heterocycles
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The pair NaBH4-TMEDA as hydride source and a palladium catalyst in THF prove to be an efficient system for the hydrodehalogenation of halogenated heterocycles with one or more heteroatoms. In general, Pd(OAc) 2-PPh3 rapidly hydrodehalogenates reactive halo-heterocycles such as bromo-pyridines, -quinolines, -thiophenes, -indoles, -imidazoles, etc., at room temperature in very good yields, whereas in most cases PdCl2(dppf) reduces less reactive halides such as chloro-pyridines, -quinolines, -pyrimidines and bromo-indoles, -benzofurans, etc. Moreover, PdCl2(tbpf) shows to be even more active removing the 2- and 5-chlorine from both thiophene and thiazole rings. The reaction conditions tolerate various functional groups, allowing highly chemoselective reactions in the presence of halide, ester, alkyne, alkene and nitrile substituents. Moreover, with a proper selection of the catalyst it is also possible to obtain a good control in the regioselective hydrodehalogenation of a variety of polyhalogenated substrates.
- Chelucci, Giorgio,Figus, Susanna
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p. 191 - 209
(2014/07/21)
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- Addition of α-lithiated nitriles to azaheterocycles
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The addition of α-deprotonated nitriles to azaheteroA?-cycles followed by rearomatization is described. A simple two-step, one-pot procedure for the sequence is also presented. Georg Thieme Verlag Stuttgart New York.
- Anderson, Corey,Moreno, Jesus,Hadida, Sabine
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p. 677 - 680
(2014/04/03)
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- Synthesis of quinazolines and tetrahydroquinazolines: Copper-catalyzed tandem reactions of 2-bromobenzyl bromides with aldehydes and aqueous ammonia or amines
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An efficient synthesis of diversely substituted quinazolines and 1,2,3,4-tetrahydroquinazolines through copper-catalyzed tandem reactions of the readily available 2-bromobenzyl bromides, aldehydes, and aqueous ammonia or amines has been developed. By using ammonia and simple aliphatic amines as the nitrogen source, the present method provides a versatile and practical protocol for the synthesis of quinazolines and 1,2,3,4-tetrahydroquinazolines. Copper on the beat: An efficient, simple and economical synthesis of diversely substituted quinazolines and 1,2,3,4-tetrahydroquinazolines has been developed through copper-catalyzed tandem reactions of the readily available 2-bromobenzyl bromides, aldehydes, and aqueous ammonia or simple aliphatic amines. Copyright
- Fan, Xuesen,Li, Bin,Guo, Shenghai,Wang, Yuanyuan,Zhang, Xinying
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supporting information
p. 739 - 743
(2014/03/21)
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- A novel synthesis of quinazolines by cyclization of 1-(2-isocyanophenyl) alkylideneamines generated by the treatment of 2-(1-azidoalkyl)phenyl isocyanides with NaH
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A new and efficient method for the synthesis of quinazolines has been developed. Thus, N-[2-(1-azidoalkyl)phenyl]formamides 1 are dehydrated with POCl3 to give the corresponding 2-(1-azidoalkyl)phenyl isocyanides 2, which are then treated with NaH in DMF at 0° to give quinazolines 6 in satisfactory yields via cyclization of 1-(2-isocyanophenyl)alkylideneamine intermediates 4. This methodology can be applied to the synthesis of the 7-azaanalogs of quinazolines, i.e., pyrido[3,4-d]pyrimidines 9. Copyright
- Ezaki, Kosuke,Kobayashi, Kazuhiro
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p. 822 - 829
(2014/07/07)
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- A cooperative catalytic system of platinum/iridium alloyed nanoclusters and a dimeric catechol derivative: An efficient synthesis of quinazolines through a sequential aerobic oxidative process
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A cooperative catalytic system of heterogeneous polymer-supported bi-metallic platinum/iridium (Pt/Ir) alloyed nanoclusters and 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethyl-1, 1′-spiro-bisindane (TTSBI) enabled the facile preparation of quinazoline derivatives with low catalyst loadings and broad substrate scope under mild aerobic oxidative conditions. The ability to perform the reaction in gram-scale and under open-air conditions highlights the synthetic application of this cooperative catalytic system. Copyright
- Yuan, Hao,Yoo, Woo-Jin,Miyamura, Hiroyuki,Kobayashi, Shu
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supporting information
p. 2899 - 2904
(2013/01/15)
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- ONSH: Optimization of oxidative alkylamination reactions through study of the reaction mechanism
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(Figure presented) Oxidative alkylamination of electron-deficient (hetero)aromatic compounds, via the nucleophilic substitution of hydrogen, is a methodology that has made significant progress since the introduction of AgPy2MnO4 as oxidant. This oxidant generally gives good conversions and yields, whereas the use of KMnO4 only sometimes works equally well. In order to rationalize this, the reaction mechanism of oxidative alkylamination has been studied. 3-Nitropyridine (1), 1,3-dinitrobenzene (2), and quinazoline (3) were chosen as model substrates and n-butylamine and pyrrolidine as model alkylamines. The rate-limiting step of the mechanism for these substrate/alkylamine combinations was determined. With the use of 1H NMR spectroscopy thermodynamic properties of σ-- adduct formation were deduced and the effect of additives on the adduct formation was investigated. The fundamental insights resulting from these studies led to the identification of a cheap additive (tetrabutylammonium chloride), which in combination with the standard and cheap oxidant KMnO 4 generally gave excellent yields, similar to the ones previously obtained with more expensive AgPy2MnO4.
- Verbeeck, Stefan,Herrebout, Wouter A.,Gulevskaya, Anna V.,Van Der Veken, Benjamin J.,Maes, Bert U. W.
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experimental part
p. 5126 - 5133
(2010/09/18)
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- 2-(3-Phenyl-2-piperazinyl-3,4-dihydroquinazolin-4-yl)acetic acids as antiviral agents, especially against cytomegaloviruses
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The invention relates to dihydroquinazolines and methods for the production thereof, the use thereof in the treatment and/or prophylaxis of diseases, in addition to the use thereof in the production of medicaments in the treatment and/or prophylaxis of diseases, especially for use as anti-viral agents, especially against cytomegalo viruses.
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- Crystalline (-)-6-chloro-4-cyclopropylethynyl-4-trifluoromethyl-3,4-dihydro-2(1H)-quinazolinone
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The potent reverse transcriptase inhibitor (?)-6-Chloro-4-cyclopropylethynyl-4-trifluoromethyl-3,4-dihydro-2(1H)-quinazolinone is produced in solvate and crystalline form. These forms are designated Forms 1 and 2, and are characterized by x-ray powder diffraction and differential scanning calorimetry. Pharmaceutical compositions and methods are useful for the treatment of the human immunodeficiency virus (HIV).
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- A novel ZrO2-SO42- supported palladium catalyst for syntheses of disubstituted ureas from amines by oxidative carbonylation
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The syntheses of disubstituted ureas by carbonylation of a series of amines in the presence of a sulfate modified zirconia supported palladium catalyst was investigated at an initial total pressure of 4.0 MPa and 135°C. High conversions and yields were achieved for the synthesis of symmetric dialkylureas. This supported catalyst could also be easily separated and recovered after reaction.
- Shi, Feng,Deng, Youquan,SiMa, Tianlong,Yang, Hongzhou
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p. 2161 - 2163
(2007/10/03)
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- First gold(I) complex-catalyzed oxidative carbonylation of amines for the syntheses of carbamates
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At 200 °C and 5 MPa of initial total pressure, the oxidative carbonylation of amines for the synthesis of the corresponding carbamates by Au(I) complexes as catalysts was conducted with excellent conversion and selectivity.
- Shi,Deng
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p. 443 - 444
(2007/10/03)
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- Process for the preparation of quinazolinones
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The present invention relates generally to an asymmetric synthesis of 4,4-disubstituted-3,4-dihydro-2(1H)-quinazolinones, and intermediates thereof. The target compounds are useful for the treatment of human immunodeficiency virus (HIV) as an inhibitor of reverse transcriptase.
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- Use of 2-amino-3,4-dihydroquinazolines for the production of a medicament for the treatment or prophylaxis of illnesses caused by ischemic conditions
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Methods of using 2-amino-3,4-dihydroquinazolines of formula I, or a pharmaceutically tolerable salt thereof, for the treatment or prophylaxis of illnesses caused by ischemic conditions: wherein: R1, R2 and R3 have the meanings indicated in the specification and claims.
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- Thermally stable trimetrexates and processes for producing the same
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The present invention provides for thermally stable forms of 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl] quinazoline, or trimetrexate. A crystalline 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyanilino)methyl] quinazoline monohydrate, or trimetrexate monohydrate, belonging to the space group P+E,ovs 1+EE (#2) and having a triclinic cell with dimensions of about a=7.699 ANGSTROM , b=9.606 ANGSTROM and c=13.012 ANGSTROM is disclosed. A novel Schiff base compound, 2,4-diamino-5-methyl-6-[(3,4,5-trimethoxyphenylimino)-methinyl]quinazoline, is also disclosed. The present invention further provides novel methods of producing stable trimetrexate free base compounds, including crystalline trimetrexate monohydrate. The crystalline monohydrate form provides increased stability over the anhydrous form.
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- An approach to fused pyrimidine derivatives via Schiff bases of aromatic ortho-nitrocarbaldehydes. An investigation of substituent effects on the reaction course
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The synthesis of fused pyrimidines from the Schiff bases of aromatic ortho-nitrocarbaldehydes is reported. The Schiff bases after selective reduction of the nitro group on 10% Pd/C, followed by condensation of the amines formed with orthoesters, are transformed to the corresponding imidates. Heating of the latter in a sealed tube with an excess of ammonia (or with ammonia in ethanol) gives fused pyrimidines. The influence of various substituents in the aromatic ring of the imine moiety of the Schiff bases on the overall yield of fused pyrimidine derivatives has been investigated. Moderate electron-withdrawing groups gave the best results.
- Ostrowski,Wolniewicz
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p. 705 - 713
(2007/10/03)
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- Fused polycyclic 2-aminopyrimidine derivatives
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Fused polycyclic 2-aminopyrimidines of formula (1) are described: wherein R1 is a group -L1 R2 where L1 is a covalent bond or a linker atom or group and R2 is a group -(Alk)mL2R3 where Alk is an optionally substituted aliphatic or heteroaliphatic chain, m is zero or the integer 1, L2 is a covalent bond or a linker atom or group and R3 is an optionally substituted cycloaliphatic or heterocycloaliphatic group provided that when m is zero L2 is a covalent bond; Ar is an aryl or heteroaryl group; X is a carbon or nitrogen atom; Y is a carbon or nitrogen atom; Z is a linker group; A together with X and Y forms an optionally substituted monocyclic or bicyclic aromatic or heteroaromatic group; and the salts, solvates, hydrates and N-oxides thereof. The compounds are potent and selective inhibitors of protein kinases, especially src-family protein kinases and are of use in the prophylaxis and treatment of immune diseases, hyperproliferative disorders and other diseases in which inappropriate protein kinase action is believed to have a role.
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- Carbon-carbon bond cleavage of α-hydroxybenzylheteroarenes catalyzed by cyanide ion: Retro-benzoin condensation affords ketones and heteroarenes and benzyl migration affords benzylheteroarenes and arenecarbaldehydes
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4-(α-Benzylα-hydroxybenzyl)quinazoline (4a) underwent retro-benzoin condensation catalyzed by cyanide ion to give deoxybenzoin (2a) and quinazoline (5a). Similarly, several nitrogen-containing heteroarenes (4, 9, 12, 16-19) having an α-hydroxybenzyl group at the α-position of the nitrogen underwent retro-benzoin type condensation to afford kelones (2) and heteroarenes (5). However, similar reaction of pyrazolopyrimidines (13, 14, 15) having an α-benzyl-α-hydroxybelzyl group resulted in benzyl migration, giving benzylpyrazolopyrimidines (8) and arenecarbaldehydes (3). Tetrabutylammonium cyanide (11, Bu4NCN) was a more effective cyanide ion donor than KCN (10). The retro-benzoin condensation was applied to the synthesis of 2-substituted quinazolines (38) from 2-chloro-4- aroylquinazolines (34), using the aroyl group as a protecting and electron- withdrawing group.
- Suzuki, Yumiko,Takemura, Yuki,Iwamoto, Ken-Ichi,Higashino, Takeo,Miyashita, Akira
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p. 199 - 206
(2007/10/03)
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- Carbon-carbon bond cleavage of α-hydroxybenzyl-heteroarenes to ketones and heteroarenes by catalytic action of cyanide ion based on retrobenzoin condensation
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Treatment of 4-(α-benzyl-α-hydroxybenzyl)quinazoline (2a) with potassium cyanide in DMF resulted in carbon-carbon bond cleavage to give benzyl phenyl ketone (3a) and quinazoline (4). Similar results were obtained with other 4-(α-hydroxybenzyl)quinazolines (2b-f and 7a). This reaction proceeds through retrobenzoin condensation. This condensation also proceeded in pyrazolopyrimidine (9a) triazolopyrimidine (10a), quinoxaline (11a), and benzimidazole (12a), and the imidazolium salt (16) was an effective catalyst.
- Miyashita, Akira,Suzuki, Yumiko,Takemura, Yuki,Iwamoto, Ken-Ichi,Higashino, Takeo
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- Palladium complex-catalyzed intermolecular reductive N-heterocyclization: novel synthesis of quinazoline derivatives from 2-nitrobenzaldehyde or 2-nitrophenyl ketones with formamide
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A combination of the palladium complex PdCl2(PPh3)2 with MoCl5 shows a high catalytic activity for the intermolecular reductive N-heterocyclization of 2-nitrobenzaldehyde or 2-nitrophenyl ketones with formamide to give the corresponding quinazoline derivatives in moderate yields.For example, in the reaction of 2-nitrobenzaldehyde with formamide, quinazoline was obtained in 46percent yield.We assume that the present reaction proceeds via an active nitrene intermediate which could be generated by selective deoxygenation of nitro group by carbon monoxide.Keywords: Palladium; Molybdenum; Carbon monoxide; Nitrene; Reductive N-heterocyclization
- Akazome, Motohiro,Yamamoto, Jun,Kondo, Teruyuki,Watanabe, Yoshihisa
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p. 229 - 234
(2007/10/02)
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- ANTIPROLIFERATIVE QUINAZOLINES
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Quinazoline compounds which demonstrate antiproliferative activity, such as antitumor activity, processes of preparing these compounds, pharmaceutical compositions containing these compounds, and the use of these compounds. These compounds inhibit the growth and proliferation of the cells of higher organisms and microorganisms,such as bacteria, yeasts and fungi. Preferred quinazoline compounds are capable of inhibiting the enzyme thymidylate synthase. Effects derived from the inhibition of the enzyme thymidylate synthase include those discussed above
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- Novel diazines and their method of preparation
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A method of preparation of substituted halogenodiazines which are useful as intermediates in the synthesis of novel unfused heterobicyclic compounds, and the products thereof. The reaction consists of the addition of an organolithium reagent with subsequent dehydrogenation of the addition product. The reaction takes place in one reaction vessel, without isolation of the substituted halogenodihydrodiazine intermediate. The reactions proceed at moderate temperature and in a short amount of time, which decreases the probability of side reactions and increases yield. Furthermore, the workup step is conducted under two-phase conditions to prevent hydrolysis of the substituted halogenodiazine to a substituted hydroxydiazine. The method is easy, efficient and results in a high yield of product. The substituted halogenodiazines are used as intermediates in the synthesis of novel unfused heterobicyclic compounds containing an aromatic moiety, diazine, and another aromatic moiety, such as thiophene, benzene, or naphthalene, which have biological activity.
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- Chromogenic quinazolines
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Chromogenic quinazolines of formula STR1 wherein R is an aryl radical or a heterocyclic radical, Z1 is oxygen or sulfur, Z2 is oxygen, sulfur or STR2 R' is hydrogen, alkyl which is unsubstituted or substituted by halogen, cyano or lower alkoxy, or is cycloalkyl, phenyl, benzyl, phenethyl or acyl, or --NRR' is a 5- or 6-membered heterocyclic radical, Q is an aliphatic radical which may be interrupted by a further member Z2, Y is the radical of a couplable compound, and the ring A is unsubstituted or substituted by halogen, cyano, nitro, lower alkyl, lower alkoxy or lower alkoxycarbonyl. These quinazolines are exceedingly fast to sublimation and are particularly suitable color formers in pressure-sensitive or heat-sensitive recording materials and give strong and lightfast yellow and orange colorations.
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- ADDITION OF PHTHALIMIDONITRENE TO SUBSTITUTED INDOLES
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The aziridine 2a obtained by the addition of phthalimidonitrene to N-phenylsulphonylindole was treated with methanolic potassium hydroxide to give desulphonated indole and quinazoline.The aziridine 2b and 2c derived from phthalimidonitrene and 2-methylindole or 2-phenylindole were treated with dimsyl anion to give 2-methylquinazoline and 2-phenylquinazoline.However the nitrene adducts 2d and 2e derived from 1,2,3,4-tetrahydrocarbazole and 1-oxo-1,2,3,4-tetrahydrocarbazole afford carbazole and 1-hydroxycarbazole under similar conditions.Hydrozinolysis of the nitrene adducts 2a, b, c, d and e regenerated the parent indole.
- Kumar, Perumal Raja
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p. 1257 - 1262
(2007/10/02)
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- Addition of Phthalimidonitrene to Substituted N-Benzenesulphonylindoles
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The aziridines (2a,b) obtained by the addition of phthalimidonitrene to N-benzenesulphonylindole and N-benzenesulphonyl-2-phenylindole, respectively give the substituted quinazolines (3a,b) and the parent indole, when treated with methanolic KOH.However, the nitrene adduct 2c derived from N-benzenesulphonyl-1-oxo-1,2,3,4-tetrahydrocarbazole under similar condition gives 1-hydroxycarbazole and 1-oxo-1,2,3,4-tetrahydrocarbazole (4c).Hydrazinolysis of the aziridines (2a,b,c) gives N-sulphonated indoles through the N-amidoaziridine intermediate.
- Kumar, P. Raja
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p. 725 - 727
(2007/10/02)
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- Transformation of Quinazoline into 2(1H)-Quinolinones with Alkanoic Anhydrides
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Quinazoline (1) was transformed into 3-substituted 2(1H)-quinolinones (4) by reaction with alkanoic anhydrides (3).Similar transformation was also found to occur with 5-methyl-1-phenyl-1H-pyrazolopyrimidinium iodide (9), giving 5-substituted 1-phenyl-1H-pyrazolo-pyridine-6-yl alkanoates (10).Keywords-quinazoline; quinolinone; alkanoic anhydride; ring transformation; pyrazolo-pyrimidinium salt; pyrazolopyridine
- Higashino, Takeo,Goto, Ayako,Miyashita, Akira,Hayashi, Eisaku
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p. 4352 - 4355
(2007/10/02)
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- Reaction of 4-Aroylquinazolines with Sodium Hydroxide: Aryl Migration to Give 4-Aryl-3,4-dihydro-4-quinazolinecarboxylic Acids and Formation of Quinazoline and Aroic Acids
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4-Aroylquinazolines (3) were prepared in good yields by alkaline hydrolysis of α-aryl-4-quinazolinylmethyl benzoates (15), followed by oxidation.The reaction of 3 with sodium hydroxide in dimethyl sulfoxide(DMSO) was found to proceed in two ways.One path is the aryl migration to lead to 4-aryl-3,4-dihydro-4-quinazolinecarboxylic acids (4), and the other is the fission of the C4-CO bond to yield quinazoline (5) and aroic acids (6). Potassium ferricyanide oxidized the carboxylic acids 4 to the corresponding 4-arylquinazolines (14) with elimination of carbon dioxide. Reaction of 4-benzoylquinazoline (3a) with methylmagnesium iodide did not result in the migration, but instead yielded of α-methyl-α-phenyl-4-quinazolinemethanol (18) and 3,4-dihydro-α,4-dimethyl-α-phenyl-4-quinazolinemethanol (19).
- Higashino, Takeo,Takemoto, Masumi,Hayashi, Eisaku
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p. 1351 - 1359
(2007/10/02)
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- Preparation and Reactions of Mono-Reissert Compounds and Analogs at the 3,4-Position of Quinazoline
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Quinazoline, acid chlorides, and trimethylsilyl cyanide have been converted to mono-Reissert compounds at the 3,4-position of the quinazoline system.Various reactions of these quinazoline Reissert compounds are reported.
- Kant, Joydeep,Popp, Frank D.,Uff, Barrie C.
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p. 1313 - 1316
(2007/10/02)
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- Preparation and Reactions of Quinazoline Reissert Compound (3-Benzoyl-3,4-dihydro-4-quinazolinecarbonitrile)
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The benzoylation of 3,4-dihydro-4-quinazolinecarbonitrile (3) with benzoyl chloride in pyridine gave quinazoline Reissert compound (1, 3-benzoyl-3,4-dihydro-4-quinazolinecarbonitrile) in 82percent yield. The alkaline hydrolysis of 1 in methanol resulted in the formation of quinazoline (2) and benzoic acid (4).Acid hydrolysis gave 2-benzamido-2-(2-aminophenyl)acetonitrile (6), 4, and 2.The HCl salt of 1 existed predominantly in the cyclic amidinium structure of the type 8.Compound 1reacted with sodium hydride in dimethylformamide to yield 4-quinazolinecarbonitrile (9), α-phenyl-4-quinazolinylmethyl benzoate (10) and O-benzoylbenzoin (11). In the present paper we compare the chemical properties of 1 with those of isoquinoline Reissert compound (13, 2-benzoyl-1,2-dihydro-1-isoquinolinecarbonitrile). Keywords --- quinazoline Reissert compound; cyclic amidinium cation; alkaline hydrolysis; acid hydrolysis; quinazoline Reissert compound anion; acetonitrile derivative; 4-quinazolinecarbonitrile; 4-quinazolinylmethyl benzoate derivative
- Higashino, Takeo,Kokubo, Hiroyasu,Hayashi, Eisaku
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p. 3900 - 3905
(2007/10/02)
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- Process for preparing pyrazolo[1,5-c]-quinazoline derivatives and novel intermediates
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A process is provided for preparing pyrazolo-[1,5-c]quinazoline derivatives of the structure STR1 wherein X is O or S; R1 is hydrogen, lower alkyl, hydroxymethyl, phenyl-lower alkyl, phenyl or phenyl substituted with halogen, lower alkyl, lower alkoxy, or trifluoromethyl; R2 is lower alkoxy, phenyl-lower alkoxy, phenoxy, or phenoxy substituted with lower alkyl or lower alkoxy; and R3 and R4 are the same or different and are selected from the group consisting of hydrogen, alkyl of 1 to 4 carbons, alkoxy of 1 to 4 carbons, lower alkanoyloxy of 1 to 4 carbons, nitro, benzyloxy, benzyloxy having a single monolower alkoxy substituent, halogen, hydroxy, and trifluoromethyl, wherein quinolone compounds of the structure STR2 which are new intermediates, are reacted with a hydrazine compound to form a 5-(2-aminophenyl)-pyrazole which is then cyclized to the product. In addition, the above product may be reacted with a halogen acid to form the corresponding hydroxymethyl compound.
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