- INVESTIGATION OF SOME ELECTROPHILIC REACTIONS OF 4-PHENYL-5-HYDROXYPYRIMIDINE AND ITS 1-OXIDE
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A difference in the reactivities of the 2 and 6 positions of the 5-hydroxypyrimidine ring and an effect of the N-oxide group on the direction of electrophilic substitution reactions were demonstrated in the case of synthesized 4-phenyl-5-hydroxypyrimidine and its 1-oxide.
- Gashev, S. B.,Sedova, V. F.,Smirnov, L. D.,Mamaev, V. P.
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- Catalyst free synthesis of mono- and disubstituted pyrimidines from O-acyl oximes
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Transition-metal or iodine catalyzed transformations of O-acyl oximes to various N-heterocycles are well established. Herein, we report a catalyst free, oxime carboxylate based, three-component condensation method to access mono- and disubstituted pyrimidines. A broad range of substituted pyrimidines were prepared in moderate to excellent yields. Control experiments reveal that in situ generated formamidine is the key intermediate.
- Upare, Atul,Sathyanarayana, Pochampalli,Kore, Ranjith,Sharma, Komal,Bathula, Surendar Reddy
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p. 2430 - 2433
(2018/05/23)
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- Transition-Metal-Free Decarboxylative Arylation of 2-Picolinic Acids with Arenes under Air Conditions
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A facile, transition-metal-free, and direct decarboxylative arylation of 2-picolinic acids with simple arenes is described. The oxidative decarboxylative arylation of 2-picolinic acids with arenes proceeds readily via N-chloro carbene intermediates to afford 2-arylpyridines in satisfactory to good yields under transition-metal-free conditions. This new type of decarboxylative arylation is operationally simple and scalable and exhibits high functional-group tolerance. Various synthetically useful functional groups, such as halogen atoms, methoxycarbonyl, and nitro, remain intact during the decarboxylative arylation of 2-picolinic acids.
- Zhang, Xitao,Feng, Xiujuan,Zhou, Chuancheng,Yu, Xiaoqiang,Yamamoto, Yoshinori,Bao, Ming
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supporting information
p. 7095 - 7099
(2018/11/23)
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- Selective aryl radical transfers into N-heteroaromatics from diaryliodonoium salts with trimethoxybenzene auxiliary
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We have found that a series of trimethoxybenzene-based diaryliodonium(III) salts I (ArI+Ar’X-, where Ar = various aryl groups, Ar’ = 2,4,6-trimethoxyphenyl, X- = counterion) can exclusively cause Ar-transfers during the base-induced radical couplings with N-heteroaromatic compounds 1 by working the trimethoxybenzene ring (Ar’) as an inert coupling auxiliary. By the treatment with N-heteroaromatics 1 as the solvent, the metal-free arylations utilizing the specific salts I initiated by solid NaOH upon heating selectively produced the corresponding biaryls 2 in good yields without the formation of the trimethoxybenzene (Ar’) coupling product.
- Dohi, Toshifumi,Ueda, Shohei,Hirai, Akiko,Kojima, Yusuke,Morimoto, Koji,Kita, Yasuyuki
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p. 1272 - 1284
(2019/11/14)
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- Preparation method of polysubstituted pyrimidine
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The invention belongs to the field of chemical synthesis, and particularly relates to a preparation method of polysubstituted pyrimidine. The method comprises the following step that amidine hydrochloride and a propiophenone compound react in the presence of an iron source compound, 1,10-phenanthroline and tetramethyl piperidine nitric oxide to obtain polysubstituted pyrimidine, wherein propiophenone or a propiophenone derivative is adopted as the propiophenone compound. According to the method, polysubstituted pyrimidine can be generated through a reaction by taking the propiophenone compound and amidine hydrochloride as reacting raw materials under combined promotion of the iron source compound, 1,10-phenanthroline and the tetramethyl piperidine nitric oxide; a strong alkaline or strong acidic environment is not needed, the reaction conditions are simple and mild, and the yield of polysubstituted pyrimidine is high. Experiment results show that the maximum yield of polysubstituted pyrimidine prepared through the method can reach 93% or above.
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Paragraph 0141; 0142; 0143; 0144; 0145; 0146; 0147
(2017/07/26)
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- Iron Catalysis for Modular Pyrimidine Synthesis through β-Ammoniation/Cyclization of Saturated Carbonyl Compounds with Amidines
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An efficient method for the modular synthesis of various pyrimidine derivatives by means of the reactions of ketones, aldehydes, or esters with amidines in the presence of an in situ prepared recyclable iron(II)-complex was developed. This operationally simple reaction proceeded with broad functional group tolerance in a regioselective manner via a remarkable unactivated β-C-H bond functionalization. Control experiments were performed to gain deep understanding of the mechanism, and the reactions are likely to proceed through a designed TEMPO complexation/enamine addition/transient α-occupation/β-TEMPO elimination/cyclization sequence.
- Chu, Xue-Qiang,Cao, Wen-Bin,Xu, Xiao-Ping,Ji, Shun-Jun
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p. 1145 - 1154
(2018/06/18)
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- Pd-catalyzed decarboxylative cross-coupling of sodium pyrimidinecarboxylates with (hetero)aryl bromides
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A straightforward method for the synthesis of functionalized 4- or 5-(hetero)arylpyrimidines via decarboxylative cross-coupling reaction from readily available pyrimidine-4- and pyrimidine-5-carboxylates was described. In the presence of dual-catalyst system of Pd(PPh3)4/Cu2O, the reaction proceeds smoothly, tolerates a variety of functional groups, and provides easy access to the synthesis of different (hetero)arylpyrimidines compounds.
- Wang, Shengqiang,Lu, Hongtao,Zou, Dapeng,Wu, Yangjie,Li, Jingya,Wu, Yusheng,Zou, Dapeng,Wu, Yusheng,Li, Jingya
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supporting information
p. 2723 - 2726
(2017/06/23)
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- Oxidative Annulations Involving DMSO and Formamide: K2S2O8 Mediated Syntheses of Quinolines and Pyrimidines
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An efficient strategy toward 4-arylquinolines and 4-arylpyrimidines from readily available precursors is described. Oxidative annulation promoted by K2S2O8 involving anilines, aryl ketones, and DMSO as a methine (=CH-) equivalent leads to 4-arylquinolines via a cascade that entails generation of a sulfenium ion, subsequent C-N and C-C bond formations, and cyclization. The application of this strategy to the activation of acetophenone-formamide conjugates toward the synthesis of 4-arylpyrimidines is also described.
- Jadhav, Santosh D.,Singh, Anand
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supporting information
p. 5673 - 5676
(2017/10/25)
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- Lewis acid-catalyzed borono-minisci reactions of arylboronic acids and heterocycles
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A Lewis acid-catalyzed Minisci reaction between arylboronic acids and heterocycles has been developed. This radical-coupling reaction was demonstrated employing several different heterocycles as well as electron-rich arylboronic acids. Quinoline substrates afforded modest regioselectivity for substitution at the 4-position under the reaction conditions, in contrast to previously reported Br?nsted acid-mediated reactions with quinoline substrates that favored substitution at the 2-position.
- Biaco, Joyce L.,Jones, Savannah L.,Barker, Timothy J.
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p. 1687 - 1697
(2016/10/12)
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- A novel graphene-supported palladium catalyst for suzuki-miyaura coupling of less reactive heteroaryl halides in water
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An efficient reduced graphene oxide-supported heterogenized palladium complex with pyrene-tagged ketoiminato ligand has been developed and used for cross-coupling of less reactive heteroaryl halides in water. Desirable catalytic activity was observed with high (up to 98%) conversion of the less reactive reactants under relatively mild conditions. The efficiency and green nature of the catalyst were confirmed without significant loss of activity.
- Taher, Abu,Lee, Dong-Jin,Lee, Ik-Mo,Rahman, Md. Lutfor,Sarker, Md Shaheen
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p. 1478 - 1485
(2016/10/11)
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- Synthesis, and docking studies of phenylpyrimidine-carboxamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety as c-Met inhibitors
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Four series of phenylpyrimidine-carboxamide derivatives bearing 1H-pyrrolo[2,3-b]pyridine moiety (14a-e, 15a-g, 16a-e and 17a-g) were designed, synthesized and evaluated for the IC50 values against three cancer cell lines (A549, PC-3 and MCF-7). Four selected compounds (15e, 16a-b and 17a) were further evaluated for the activity against c-Met kinase, HepG2 and Hela cell lines. Most of the compounds showed excellent cytotoxicity activity and selectivity with the IC50 valuables in single-digit μM to nanomole range. Eleven of them are equal to more active than positive control Foretinib against one or more cell lines. The most promising compound 15e showed superior activity to Foretinib against A549, PC-3 and MCF-7 cell lines, with the IC50 values of 0.14 ± 0.08 μM, 0.24 ± 0.07 μM and 0.02 ± 0.01 μM, which were 4.6, 1.6 and 473.5 times more active than Foretinib (0.64 ± 0.26 μM, 0.39 ± 0.11 μM, 9.47 ± 0.22 μM), respectively. Structure-activity relationships (SARs) and docking studies indicated that the replacement of phenylpicolinamide scaffold with phenylpyrimidine fragment of the target compounds was benefit for the activity. What's more, the introduction of fluoro atom to the aminophenoxy part played no significant impact on the activity and any substituent group on aryl group is unfavourable for the activity.
- Zhu, Wufu,Wang, Wenhui,Xu, Shan,Wang, Jianqiang,Tang, Qidong,Wu, Chunjiang,Zhao, Yanfang,Zheng, Pengwu
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p. 1749 - 1756
(2016/04/05)
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- Synthesis, activity and docking studies of phenylpyrimidine–carboxamide Sorafenib derivatives
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Two series of Sorafenib derivatives bearing phenylpyrimidine–carboxamide moiety (16a–g and 17a–p) were designed, synthesized and evaluated for the IC50values against three cancer cell lines (A549, MCF-7 and PC-3). Two selected compounds (17f and 17n) were further evaluated for the activity against VEGFR2/KDR kinase. More than half of the synthesized compounds showed moderate to excellent activity against three cancer cell lines. Compound 17f showed equal activity to Sorafenib against MCF-7 cell line, with the IC50values of 6.35 ± 0.43 μM. Meanwhile, compound 17n revealed more active than Sorafenib against A549 cell line, with the IC50values of 3.39 ± 0.37 μM. Structure–activity relationships (SARs) and docking studies indicated that the second series (17a–p) showed more active than the first series (16a–g). What's more, the introduction of fluoro atom to the phenoxy part played no significant impact on activity. In addition, the presence of electron-donating on aryl group was benefit for the activity.
- Wang, Wenhui,Wu, Chunjiang,Wang, Jianqiang,Luo, Rong,Wang, Caolin,Liu, Xiaobo,Li, Jiqing,Zhu, Wufu,Zheng, Pengwu
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p. 6166 - 6173
(2016/12/06)
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- Metal free C-H functionalization of diazines and related heteroarenes with organoboron species and its application in the synthesis of a CDK inhibitor, meriolin 1
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Here, we report a metal-free cross-coupling reaction of diazines and related heteroarenes with organoboron species via C-H functionalization. The optimized conditions represent a metal-free method for the activation of aryl/heteroarylboronic acids, which undergo coupling with diazines and related heteroarenes. Optimized conditions also find application in the synthesis of a pyrimidine-based potent CDK inhibitor, meriolin1.
- Thatikonda, Thanusha,Singh, Umed,Ambala, Srinivas,Vishwakarma, Ram A.,Singh, Parvinder Pal
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p. 4312 - 4320
(2016/05/24)
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- Quinoline compound and its preparation method and application (by machine translation)
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The invention relates to the general formula I shown quinoline derivatives and their pharmaceutically acceptable salt, hydrate, solvate and prodrug, wherein substituent R1 , R2 , X, Y, Z, n has the meaning given in the specification. The invention also relates to the compounds of the general formula I has strong inhibition of c - Met kinase function, and also relates to the compounds and its pharmaceutically acceptable salt, hydrate, solvate or prodrug thereof in the preparation of the treatment because the c - Met kinase abnormal high expression of diseases caused by the use of the medicaments, in particular in preparing and treating and/or preventing cancer of the use of the medicament. (by machine translation)
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Paragraph 0235; 0236
(2017/02/17)
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- Direct access to pyrimidines through organocatalytic inverse-electron-demand Diels-Alder reaction of ketones with 1,3,5-triazine
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An organocatalytic inverse-electron-demand Diels-Alder reaction of ketones with 1,3,5-triazine through enamine catalysis has been developed. This method could furnish 4,5-disubstituted pyrimidines in good yields and high levels of regioselectivities.
- Yang, Gongming,Jia, Qianfa,Chen, Lei,Du, Zhiyun,Wang, Jian
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p. 76759 - 76763
(2015/09/28)
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- Scope and limitation for FeSO4-mediated direct arylation of heteroarenes with arylboronic acids and its synthetic applications
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FeSO4-mediated direct arylation of heteroarenes with arylboronic acids in the presence of K2S2O8 has been developed. A slow addition of an aqueous solution of an iron complex was crucial in the arylation. Scope and limitation of the heteroarenes and arylboronic acids are discussed. Furthermore, the direct arylation was applied to the formal total synthesis botryllazine B and sodium channel inhibitor.
- Komeyama, Kimihiro,Nagao, Yuya,Abe, Manabu,Takaki, Ken
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p. 301 - 313
(2014/03/21)
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- One-pot and three-component synthesis of substituted pyrimidines catalysed by boron sulfuric acid under solvent-free conditions
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An efficient, simple and one-pot synthesis of pyrimidine derivatives by a three-component reaction of ketones, triethyl orthoformate, and ammonium acetate in the presence of boron sulfuric acid as a reusable and efficient catalyst under solvent-free conditions is reported. The reusability of catalyst, simplicity of the starting materials, short reaction time, one-pot, and good yields of products are the main advantages.
- Soheilizad, Mehdi,Adiba, Mehdi,Sajjadifarb, Sami
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p. 524 - 527
(2014/12/10)
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- One-pot synthesis of pyrimidines under solvent-free conditions
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N,N,N',N'-Tetrabromobenzene-1,3-disulfonamide was used as an efficient catalyst for the one-pot synthesis of pyrimidine derivatives in excellent yields from triethoxymethane, ammonium acetate, and various ketone derivatives at 100-110 °C under solvent-fre
- Ghorbani-Vaghei, Ramin,Karimi-Nami, Rahman,Toghraei-Semiromi, Zahra,Amiri, Mostafa,Salimi, Zahra,Ghavidel, Mehdi
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p. 324 - 330
(2014/04/17)
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- Fast and green one-pot multicomponent synthesis of a library of pyrrolo[1,2-c] pyrimidines under microwave irradiation
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A simple, clean and rapid one-pot three component, microwave-assisted synthesis of pyrrolo[1,2-c]pyrimidine derivatives starting from various substituted pyrimidines, 2-bromoacetophenones and nonsymmetrical, electron deficient alkynes in 1,2-epoxybutane which acts both as solvent and acid scavenger is reported. This one-pot three component synthesis implies short reaction times being at the same time highly cost-effective and environmental friendly.
- Georgescu, Emilian,Georgescu, Florentina,Draghici, Constantin,Cristian, Liliana,Popa, Marcel Mirel,Dumitrascu, Florea
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p. 851 - 857
(2014/03/21)
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- Visible light-mediated direct arylation of arenes and heteroarenes using diaryliodonium salts in the presence and absence of a photocatalyst
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Diaryliodonium salts have been used as aryl radical sources under visible light-mediated photoredox catalysis. Benzene and a range of heteroarenes are arylated with Ar2I+ in the presence of [Ir(ppy)2(bpy)] PF6 upon irradiation with visible light. When pyrroles are used, the arylation proceeds in the absence of a photoredox catalyst. Both processes are initiated by photoinduced single-electron-transfer to Ar2I+, generating aryl radicals.
- Tobisu, Mamoru,Furukawa, Takayuki,Chatani, Naoto
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supporting information
p. 1203 - 1205
(2013/10/22)
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- Design, synthesis, and structure-activity relationships of novel 6,7-disubstituted-4-phenoxyquinoline derivatives as potential antitumor agents
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Two series of quinoline derivatives bearing the pyridine/pyrimidine scaffold were synthesized, and evaluated for their c-Met kinase inhibitory activity and antiproliferative activity against 5 cancer cell lines (HT-29, H460, MKN-45, A549, and U87MG) were evaluated in vitro. Most compounds showed moderate to excellent potency, and compared to foretinib, the most promising analog 18b (c-Met half-maximal inhibitory concentration [IC50] = 1.39 nM) showed a 7.3-fold increase in activity against HT-29 cell line in vitro. Structure-activity relationship studies indicated that regulation of the electron density on the pyridine/pyrimidine ring to a proper degree was a key factor in improving the antitumor activity.
- Tang, Qidong,Zhao, Yanfang,Du, Xinming,Chong, Lian'E,Gong, Ping,Guo, Chun
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- Mechanistic aspect of ring transformations in the reaction of 5-nitro-4-pyrimidinone with acetophenone derivatives and cycloalkanones depending on the electron density/ring size of the ketone
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3-Methyl-5-nitro-4-pyrimidinone undergoes two kinds of nucleophilic type ring transformations upon treatment with cycloalkanones in the presence of ammonium acetate, which affords 4,5-disubstituted pyrimidines and 5,6-disubstituted 3-nitro-2-pyridones. In order to improve the synthetic utility of this reaction, it is necessary to control the regioselectivity of these ring transformations. In the present work, we performed DFT calculation to realize the selectivity of two ring transformation products. In cases of adduct intermediates derived from cyclohexanone and cyclooctanone, the 2-attack proceeds preferably to give condensed pyrimidines. On the other hand, the adduct intermediate derived from cycloheptanone undergoes the 4-attack predominantly to afford condensed nitropyridone.
- Nishiwaki, Nagatoshi,Sugimoto, Ryuichi,Saigo, Kazuhiko,Kobiro, Kazuya
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supporting information
p. 956 - 959
(2013/03/13)
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- Iron-mediated direct arylation with arylboronic acids through an aryl radical transfer pathway
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A novel iron-mediated direct C-H arylation of quinones and pyridine analogues with arylboronic acids has been developed using dichloromethane and water as solvents at ambient temperature. FeS is employed and serves as an efficient catalyst. A detailed reaction mechanism is speculated and expounded.
- Wang, Jian,Wang, Shan,Wang, Gao,Zhang, Ji,Yu, Xiao-Qi
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supporting information
p. 11769 - 11771
(2013/01/15)
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- A method for the reductive scission of heterocyclic thioethers
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A mild, chemoselective, and generally high-yielding method for the reductive scission of heterocyclic thioethers is described. Suitable heterocycles have a thioether substituent at the 2-position relative to a ring heteroatom. The convenient and straightforward method is demonstrated with reactants which are not compatible with the standard Raney nickel conditions such as sulfides, sulfones, and thiophenes. In addition, benzyl esters, benzyl amides, and benzyl carbamates are tolerated by the reductive reaction conditions.
- Graham, Thomas H.,Liu, Wensheng,Shen, Dong-Ming
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supporting information; experimental part
p. 6232 - 6235
(2012/01/03)
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- One-pot synthesis of pyrimidines via cyclocondensation of β-bromovinyl aldehydes with amidine hydrochlorides
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A series of pyrimidines were prepared by cyclocondensation of β-bromovinyl aldehydes with amidine hydrochlorides in the presence of Et3N in excellent yields (74-95%).
- Yan, Shengjiao,Tang, Yajuan,Yu, Fuchao,Lin, Jun
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experimental part
p. 487 - 490
(2011/04/22)
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- General and highly active catalyst for mono and double Hiyama coupling reactions of unreactive aryl chlorides in water
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A new β-diketiminatophosphane Pd catalyst was found to be highly effective in the mono and double Hiyama coupling reactions of unactivated aryl chlorides in water.
- Lee, Dong-Hwan,Jung, Ji-Young,Jin, Myung-Jong
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supporting information; experimental part
p. 9046 - 9048
(2011/02/17)
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- Highly active and recyclable silica gel-supported palladium catalyst for mild cross-coupling reactions of unactivated heteroaryl chlorides
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Silica gel-supported β-ketoiminatophosphane-Pd complex (Pd@SiO 2) was shown to be a highly active and long-lived catalyst for aqueous Suzuki, Stille and Sonogashira coupling reactions of heteroaryl chlorides. A wide range of heteroaryl chlorides could be efficiently coupled with different nucleophilic partners in the presence of only 0.5 mol% catalyst and under mild conditions. This is one of the most powerful heterogeneous catalysts for the couplings of diverse heteroaryl chlorides. Furthermore, the catalyst could be reused with almost consistent activity. The Royal Society of Chemistry 2010.
- Lee, Dong-Hwan,Jung, Ji-Young,Jin, Myung-Jong
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experimental part
p. 2024 - 2029
(2011/02/22)
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- Room temperature Stille cross-coupling reaction of unreactive aryl chlorides and heteroaryl chlorides
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Phosphanyl-β-ketoiminate Pd complexes serve as highly effective catalysts in the Stille coupling reaction of aryl chlorides and heteroaryl chlorides with organostannanes at room temperature.
- Lee, Dong-Hwan,Taher, Abu,Ahn, Wha-Seung,Jin, Myung-Jong
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supporting information; scheme or table
p. 478 - 480
(2010/05/01)
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- Titanium catalyzed one-pot multicomponent coupling reactions for direct access to substituted pyrimidines
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A titanium-catalyzed 3-component coupling reaction can be used to generate tautomers of 1,3-diimines. These diimines produced in situ undergo condensation with amidines in a one-pot procedure to provide substituted pyrimidines. Seventeen examples of pyrimidines are provided using this one-pot, 4-component procedure from simple starting materials. In some cases, catalyst architecture can be tuned to control the regioselectivity of the alkyne addition. Finally, the regioselectivity of amidine addition to unsymmetrical 1,3-diimines is discussed.
- Majumder, Supriyo,Odom, Aaron L.
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experimental part
p. 3152 - 3158
(2010/06/11)
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- Expanded heterogeneous Suzuki-Miyaura coupling reactions of aryl and heteroaryl chlorides under mild conditions
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A mesoporous LTA zeolite (MP-LTA)-supported palladium catalyst was developed for the highly efficient Suzuki-Miyaura reaction of aryl and heteroaryl chlorides. The couplings of various aryl chlorides with arylboronic acids in aqueous ethanol were efficiently achieved in the presence of 1.0 mol% of the catalyst. Furthermore, the scope of this catalyst was extended to the coupling of heteroaryl chlorides. Regardless of the substituents, all of the coupling reactions were very clean and highly efficient under mild heating. It shows that our catalyst is one of the most powerful heterogeneous catalysts for the coupling of a wide range of aryl and heteroaryl chlorides. The catalyst could be repetitively used at least 10 times without a significant loss of its catalytic activity. Compared to mesoporous SBA-15 and MCM-41 materials, the MP-LTA support proved to be very stable and robust to prevent degradation upon reuse.
- Lee, Dong-Hwan,Choi, Minkee,Yu, Byung-Woo,Ryoo, Ryong,Taher, Abu,Hossain, Shahin,Jin, Myung-Jong
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supporting information; experimental part
p. 2912 - 2920
(2010/04/01)
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- An unprecedented approach to 4,5-disubstituted pyrimidine derivatives by a ZnCl2-catalyzed three-component coupling reaction
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We have developed a ZnCI2-catalyzed three-component coupling reaction involving a variety of functionalized enamines, triethyl orthoformate, and ammonium acetate, which leads to the production of 4,5-disubstituted pyrimidine derivatives in a single step. The procedure can be successfully applied to the efficient synthesis of mono- and disubstituted pyrimidine derivatives, using methyl ketone derivatives instead of enamines.
- Sasada, Toshiaki,Kobayashi, Fuminori,Sakai, Norio,Konakahara, Takeo
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supporting information; experimental part
p. 2161 - 2164
(2009/09/28)
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- Potassium t-butoxide alone can promote the biaryl coupling of electron-deficient nitrogen heterocycles and haloarenes
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(Chemical Equation Presented) The biaryl coupling of electron-deficient nitrogen heterocycles and haloarenes can be promoted by potassium t-butoxide alone, without the addition of any exogenous transition metal species. Electron-deficient nitrogen heterocycles such as pyridine, pyridazine, pyrimidine, pyrazine, and quinoxaline are arylated with haloarenes. Control experiments support a radical-based mechanism. Taking these findings into account, radical processes may be partially involved in the reported transition-metal-catalyzed arylation reactions employing t-butoxide bases and haloarenes under elevated temperatures or under microwave irradiation.
- Yanagisawa, Shuichi,Ueda, Kirika,Taniguchi, Tadashi,Itami, Kenichiro
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supporting information; scheme or table
p. 4673 - 4676
(2009/05/13)
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- One-step synthesis of 4,5-disubstituted pyrimidines using commercially available and inexpensive reagents
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4,5-Disubstituted pyrimidines are synthesized from the corresponding ketone in one-step using inexpensive reagents (formamidine acetate, n-propanol, heat). Contrasted to other methods, this process appears quite amenable to large-scale use in industrial settings.
- Baran, Phil S.,Shenvi, Ryan A.,Nguyen, Steven A.
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p. 581 - 586
(2008/02/02)
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- Synthesis of a novel series of 6,6′-disubstituted 4,4′-bipyrimidines by radical anion coupling: New π-accepting ligands for coordination chemistry
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A new family of 6,6′-disubstituted 4,4′-bipyrimidine ligands has been prepared and characterized. The reduction potentials of the new ligands, as determined by cyclic voltammetry, indicate that these new ligands are considerably better π-acceptors than the ubiquitous 2,2′-bipyridine ligand, and are even superior to the parent unsubstituted 4,4′- bipyrimidine ligand. The substituents in 6,6′ positions of the 4,4′-bipyrimidine also cause a red-shift in the π→π* and n→π* absorptions throughout the UV region. The X-ray crystal structure of one member of the family of bipyrimidines demonstrates that the aryl substituents may lie coplanar with the pyrimidine rings in the solid state. The additional electron delocalization afforded by the aryl substituents on the pyrimidine rings contribute to the better π-accepting ability of these compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Ioachim, Elena,Medlycott, Elaine A.,Polson, Matthew I. J.,Hanan, Garry S.
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p. 3775 - 3780
(2007/10/03)
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- Synthesis of pyrimidines from ketones using microwave irradiation
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A simple, high yielding synthesis of pyrimidines from ketones in the presence of HMDS and formamide is described. Under microwave irradiation, heteroaromatic, aryl, aliphatic, and cyclic ketones cyclized to give pyrimidines in good yields.
- Tyagarajan, Sriram,Chakravarty, Prasun K.
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p. 7889 - 7891
(2007/10/03)
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- Palladium-catalysed synthesis of pyrimidines
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Satisfactory yields of 4-substituted pyrimidines and bicyclic pyrimidines are produced from α-methyl or α-methylene ketones when reacted with formamide and tetrakis(triphenylphosphine)palladium(0) or a 1:2 mixture of palladium(II) acetate and triphenylphosphine as catalysts. Under the same reaction conditions pyridines or imidazole are formed from 1,3- or 1,2-diketones.
- Ingebrigtsen, Truls,Helland, Irene,Lejon, Tore
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p. 2593 - 2603
(2007/10/03)
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- Novel synthesis of bihetaryl compounds
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The ring transformation of nitropyrimidinone 1 with acetophenone derivatives 2 affords two kinds of azaheterocyclic compounds, 4-phenylpyrimidines 3 and 3-nitro-6-phenyl-2-pyridones 4. On the basis of the relationship between electronic properties of the substituent and ratios of products, a plausible reaction mechanism is provided. Furthermore, the present reaction could be applied to heterocyclic ketones giving bihetaryl compounds.
- Nishiwaki, Nagatoshi,Yamashita, Keiko,Azuma, Mayumi,Adachi, Tomoko,Tamura, Mina,Ariga, Masahiro
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p. 1996 - 2000
(2007/10/03)
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- Substituted triazines and pyrimidines from 1,3,5-triazine and a lithium amidinate, alkyl- or 1-azaallyl
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Treatment of 1,3,5-triazine 1 with an alkyllithium LiR [R = a Me, b Bun, c But, d Ph, e CH2TMS, f CH(TMS)2 or g Si(TMS)3(THF)3] yielded the appropriate 1 : 1 addition product 2a-2g, which upon hydrolysis gave the corresponding mono-substituted dihydro-1,3,5-triazine HNC(H)NC(H)(R)NCH 3a-3g. 1H NMR spectral data showed that the 1,4-dihydrotriazine 3f in toluene-d8 was in equilibrium with its 1,2-dihydro tautomer. Heating 3f with EtOH or H2O in an acidic medium led to the facile cleavage of a C-Si bond and the formation of EtOTMS or (TMS)2O, respectively. The 13C and 15N NMR spectral data are compared with those obtained by B3LYP/6-31+G* computations on the model compound NC(H)NCH2NCH. Treatment of 1 with the lithium amidinate [Li{N(TMS)C(Ph)NTMS}]2 or with 1-azaallyllithium [Li{N(TMS)C(Ph)C(H)TMS}(tmen)], [Li{N(TMS)C(BUt)C(H)TMS}]2 or [Li{N(TMS)C(Ph)C(TMS)2}(THF)2] yielded 2-phenyltriazine 5, 4-phenylpyrimidine 6, 4-tert-butylpyrimidine 9 or, in poor yield, the new 4-phenyl-5-trimethylsilylpyrimidine 7, respectively. In the case of 1 and [Li{N(TMS)C(BUt)C(H)TMS}]2 an intermediate was isolated - the thermally unstable [Li{N(TMS)C(H)NC(H)NC(H)C(H)C(BUt)NTMS}]n 8. A pathway is proposed involving the 1,4-addition of the lithium compound to 1,3,5-triazine 1, followed by a 1,3-trimethylsilyl shift, ring-opening and the formation of a new C-C or C-N bond to form the appropriate aromatic heterocycle.
- Boesveld,Hitchcock,Lappert
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p. 1103 - 1108
(2007/10/03)
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- Two ring transformations of 3-methyl-5-nitropyrimidin-4(3H)-one for the construction of azaheterocycles
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The reaction of 3-methyl-5-nitropyrimidin-4(3H)-one with ketones in the presence of NH3 afforded 4,5-disubstituted pyrimidines 5. Use of ammonium acetate instead of NH3 as the nitrogen source caused another ring transformation giving 5,6-disubstituted 3-nitro-2-pyridones 8 as well as 5. Pyrimidinone 1 behaved as an activated diformylamine 6 in the former reaction and as the synthetic equivalent of α-nitroformylacetic acid 9 in the latter case. The ratio of 5 and 8 produced when using NH4OAc varied with solvent. The reaction in acetic acid predominantly afforded pyrimidine 5, but in methanol the reaction afforded pyridone 8. The two types of ring transformations presented here are novel methods for the preparations of azaheterocycles.
- Nishiwaki, Nagatoshi,Adachi, Tomoko,Matsuo, Kengo,Wang, Hui-Ping,Matsunaga, Tomoko,Tohda, Yasuo,Ariga, Masahiro
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- Synthesis of 4-phenylpyrimidine from acetophenone and formamide
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Employing cuprous chloride as a catalyst in the Leuckart reaction between formamide and acetophenone leads to the formation of 4- phenylpyrimidine in satisfactory yield.
- Heiland, Irene,Lejon, Tore
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p. 611 - 615
(2007/10/03)
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- Novel ring transformation of nitropyrimidinone; synthetic equivalent of α-nitroformylacetic acid
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3-Methyl-5-nitropyrimidin-4(3H)-one reacts with ketones in the presence of ammonium salts to afford disubstituted pyrimidines and disubstituted 3-nitro-2-pyridones in a novel ring transformation reaction; nitropyrimidinone behaves as an activated diformylamine in the former case, and as a synthetic equivalent of α-nitroformylacetic acid in the latter case.
- Nishiwaki, Nagatoshi,Wang, Hui-Ping,Matsuo, Kengo,Tohda, Yasuo,Ariga, Masahiro
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p. 2261 - 2262
(2007/10/03)
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- Reaction of Triphenylsulfonium Salt with Organolithium Reagents
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The reaction of triphenylsulfonium trifluoromethanesulfonate with various nucleophilic, organolithium reagents gave ligand coupling products and the corresponding diaryl or di-heteroaryl sulfides. Moreover, ligand exchange reaction did not give any noticeable product in each reaction. Therefore, it was found that only the ligand coupling reaction proceeds in this reaction system.
- Oae,Ishihara,Yoshihara
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p. 265 - 269
(2007/10/03)
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- Selectivities in the formation of pyridines and pyrimidines by ammonia-induced cyclocondensations of vinamidiniums
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Arylvinamidines (2-, 3- or 4-aryl-4-(N,N-dimethyl)amino-1-azabuta-1,3-dienes), generated from 1,1,5,5-tetramethyl-2- or 3-phenyl-1,5-diazapentadienium salts, cyclocondense orientation-specifically under two regioselections forming 1-4'+4-3' and 1-2'+4-1' bonds on exposure to ammonia. The initial cyclates aromatise eliminatively to give mixtures of diarylpyridines and arylpyrimidines. The 2-arylvinamidines do not participate as 2-centre reactants and their 4-aryl isomers not as 4-centre reactants in the cyclocondensations which appear to be stepwise and not concerned. Reasons for the selective participation appear to be that the required eliminations from the initial cyclates are disfavoured in the first case and that a geometric factor prevents cyclate-formation in the second.
- Natarajan Balasubrahmanyam,Jeyashri, Bommuswamy,Narayanan Namboothiri, Irishi N.
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p. 8127 - 8142
(2007/10/02)
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- NOVEL SYNTHESIS OF SUBSTITUTED PYRIMIDINES: A RING TRANSFORMATION OF 3-METHYL-5-NITROPYRIMIDIN-4(3H)-ONE
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A novel ring transformation of 3-methyl-5-nitropyrimidin-4(3H)-one with ketones in the presence of ammonia was found to be an elegant method for synthesizing 5,6-disubstituted pyrimidines.Tetrahydroquinazoline was readily obtained in good yields when cyclohexanone was employed as a substrate.The present reaction was applicable to cyclopentanone, acetophenone and p-nitroacetophenone to give corresponding pyrimidine derivatives.
- Nishiwaki, Nagatoshi,Matsunaga, Tomoko,Thoda, Yasuo,Ariga, Masahiro
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p. 249 - 252
(2007/10/02)
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