- Real time HR-MAS NMR: Application in reaction optimization, mechanism elucidation and kinetic analysis for heterogeneous reagent catalyzed small molecule chemistry
-
A novel application of in situ 1H high-resolution magic angle spinning (HR-MAS) NMR technique for real-time monitoring of H2SO 4-silica promoted formation of 2, 2-disubstituted quinozolin-4(3H)-ones is reported. The detailed NMR spectroscopic data led to elucidation of the mechanism, reaction optimization, kinetics and quantitative analysis of the product accurately and efficiently. The translation of the optimized parameters obtained by 1H HR-MAS NMR in the wet laboratory provided similar results. It is proposed that 1H HR-MAS has a potential utility for optimization of various organic transformations in solid supported catalyzed reactions. Copyright
- Roy, Abhijeet Deb,Jayalakshmi,Dasgupta, Somnath,Roy, Raja,Mukhopadhyay, Balaram
-
-
Read Online
- Catalyst-free synthesis of quinazolinones by oxidative cyclization under visible light in the absence of additives
-
A general metal-free oxidative cyclization route was developed to synthesize quinazolinones under visible light. A series of substituted 2-aminobenzamides were reacted with aldehydes or ketones to produce the desired quinazolinones in good yields. Most importantly, the reaction did not require excess oxidant or high temperatures.
- Yang, Jiangnan,Xie, Zongbo,Chen, Zhongsheng,Jin, Liang,Li, Qian,Le, Zhanggao
-
p. 1496 - 1501
(2021/05/03)
-
- Heterocyclic reaction inducted by Br?nsted–Lewis dual acidic Hf-MOF under microwave irradiation
-
Use of green chemistry and alternative strategies has been explored to prepare diverse organic derivatives. The combination between heterogeneous catalyst, environmentally benign reaction and high-yielding methods is gaining momentum. Herein, a defective 6-connected Hf-MOF, named Hf-BTC, was efficiently synthesized and characterized for the heterogeneous catalysis under microwave irradiation. The MOF features including structural defect, porosity, acidity, and stability was analyzed by powder X-ray diffraction, N2 sorption isotherms, acid-base titration, and thermal gravimetric analysis. In the catalytic studies, the Br?nsted-Lewis dual acidic Hf-BTC was efficiently applied for the synthesis of the heterocyclic compounds via the microwave-assisted cycloaddition and condensation reactions. The reactions proceeded smoothly in the presence of the Hf-MOF with a broad scope of substrates provided the expected products in high to excellent yields (up to 99 %) for few minutes and the catalyst could be easily recycle over many consecutive reactions without loss of its reactivity and structure.
- Nguyen, Linh Ho Thuy,Nguyen, Trang Thi Thu,Dang, Minh-Huy Dinh,Tran, Phuong Hoang,Doan, Tan Le Hoang
-
-
- Visible light induced tandem reactions: An efficient one pot strategy for constructing quinazolinones using in-situ formed aldehydes under photocatalyst-free and room-temperature conditions
-
A facile tandem route has been developed for constructing quinazolinones from various aminobenzamides and in-situ generated aldehydes. Visible light was found to play a dual role: first oxidizes the alcohol to the aldehyde and then facilitates its cyclization with o-substituted aniline. Furthermore, alcohols are perfect alternatives to aldehydes because they are greener, more available, more economical, more stable, and less toxic than aldehydes. The first reaction step continuously provides material for the second step, which effectively reduces loss through volatilization, oxidation, and polymerization of the aldehyde, while avoiding its toxicity. A variety of quinazolinones can be prepared in the presence of visible light without any additional photocatalyst. The developed synthesis protocol proceeds with the merits of mild conditions, broad substrate scope, operational simplicity, and high atom efficiency, with an eco-energy source under metal-free, photocatalyst-free, and ambient conditions.
- Xie, Zongbo,Lan, Jin,Zhu, Haibo,Lei, Gaoyi,Jiang, Guofang,Le, Zhanggao
-
supporting information
p. 1427 - 1431
(2020/11/02)
-
- Selective synthesis of functionalized quinazolinone derivatives via biocatalysis
-
A novel and efficient biocatalyzed methodology for the construction of functionalized quinazolinone derivatives via tandem / hydrolysis / decarboxylation / cyclization and transesterification reactions has been developed that works with a variety of 2-aminobenzamide and β-dicarbonyl compounds. This method requires mild conditions, and has demonstrated high catalytic activity, excellent yields, excellent chemoselectivity, and a broad substrate scope. Additionally, biocatalyzed decarboxylation does not require high temperatures or light activation, giving it a substantial advantage over alternative techniques. Most importantly, it offers a new example for the exploration of simple, convenient, and environmentally friendly synthetic routes utilizing enzymes in organic chemistry.
- Gong, Bozhen,Lan, Jin,Le, Zhanggao,Li, Hongxia,Meng, Jia,Xie, Zongbo
-
-
- Effect of Fe(iii)-based MOFs on the catalytic efficiency of the tandem cyclooxidative reaction between 2-aminobenzamide and alcohols
-
The catalytic properties of metal-organic frameworks (MOFs) containing triangular Fe(iii) clusters in the promotion of organic syntheses and photocatalysis applications have been receiving substantial attention for decades. These clusters are appealing due to the strong Lewis acidity afforded by coordinatively unsaturated sites upon the removal of solvent from the framework. In this paper, triangular Fe(iii) cluster-based MOFs were shown to be highly efficient heterogeneous catalysts for the solvent-free one-pot condensation of 2-aminobenzamide and alcohols to form quinazolin-4-ones under microwave irradiation. The Fe-MOF catalysts ranging from microporous to mesoporous structures with a variety of geometrical pore structures were investigated. Because of the open accessible spaces for reactants and high density of active sites, MOF-907, built from trimer Fe clusters and a mixture of two linkers, was more effective than other Fe(iii)-MOFs. The catalyst can be used for a broad substrate scope and recycled several times without a significant drop-off in its activity.
- Dang, Minh-Huy Dinh,Nguyen, Trang Thi Minh,Nguyen, Linh Ho Thuy,Nguyen, Trang Thi Thu,Phan, Thang Bach,Tran, Phuong Hoang,Doan, Tan Le Hoang
-
supporting information
p. 14529 - 14535
(2020/10/02)
-
- Microwave-assisted synthesis of quinazolin-4(3H)-ones catalyzed by SbCl
-
Antimony(III) trichloride (SbCl3) is an effective catalyst (1 mol%) for the condensation of anthranilic amide with various aldehydes or ketones to quinazolin-4(3H)-one derivatives in good to excellent yields under microwave irradiation. The process is carried out within several minutes under solvent-free conditions. This general methodology has the advantages of simplicity, mild reaction conditions and high yields of products.
- Kang, Huaiyuan,Wang, Weili,Sun, Qinqiang,Yang, Shuya,Jin, Juan,Zhang, Xuewen,Ren, Xiaoliang,Zhang, Jiming,Zhou, Jianhua
-
p. 293 - 296
(2018/11/27)
-
- The Remarkable Cooperative Effect of a Br?nsted-Acidic Ionic Liquid in the Cyclization of 2-Aminobenzamides with Ketones
-
An unprecedented role of an imidazolium Br?nsted acidic ionic liquid was found in the formation of 2,2-disubstituted quinazolin-4(1H)-one derivatives; both the C2-H of the imidazolium moiety and an acidic proton were necessary and simultaneously took part in the catalysis. A library of quinazolin-4(1H)-ones was prepared from readily available ketones and 2-aminobenzamides; excellent yields were obtained through simple crystallization under solvent-free conditions with lower E factors. The catalyst could be reused over five consecutive runs without any significant loss in catalytic activity. This method produces only water as a byproduct and represents a green synthetic protocol. A clean reaction, no chromatographic purification, easily accessible reactants, a metal-free and solvent-free process, and environmentally friendly reaction conditions are the notable advantages of this procedure. The possible role of the C2-H of the imidazolium moiety in catalysis was studied by mass spectrometry.
- Das, Sudarshan,Santra, Sougata,Jana, Sourav,Zyryanov, Grigory V.,Majee, Adinath,Hajra, Alakananda
-
p. 4955 - 4962
(2017/09/13)
-
- Facile method for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones catalyzed by SiO2–H3PW12O40 in water
-
The 12-tungstophosphoric acid supported on silica gel (PW/SiO2) exhibits excellent activity in the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by cyclocondensation reaction of 2-aminobenzamide with carbonyl compounds in water under reflux conditions. The desired products have been obtained in short reaction times in high yields. Our method has been successfully applied for both aldehydes and ketones (aromatic and aliphatic). Easy recovery and reusable catalyst, easy work-up and avoidance of using harmful organic solvents are the major advantages of our method in comparison to existing methods.
- Alinezhad, Heshmatollah,Soleymani, Elham,Zare, Mahboobeh
-
p. 457 - 466
(2017/01/14)
-
- Expeditious synthesis of 2,3-dihydroquinazolin-4(1H)-ones in aqueous medium using thiamine hydrochloride (VB1) as a mild, efficient, and reusable organocatalyst
-
A simple and straightforward synthesis of 2,3-dihydroquinazolin-4(1H)-ones is developed by reacting anthranilamide with various aldehydes or ketones under mild reaction conditions, using thiamine hydrochloride as a cost-effective, readily available, and green catalyst in water. Simple purification process, high yields within short reaction time, wide substrate scope, operational simplicity, and reusability of the catalyst up to three cycles enrich the applicability of the protocol.
- Devi, Jutika,Kalita, Subarna Jyoti,Deka, Dibakar Chandra
-
supporting information
p. 1601 - 1609
(2017/09/08)
-
- Ethanol promoted titanocene Lewis acid catalyzed synthesis of quinazoline derivatives
-
An efficient catalytic system involving in situ activation of kinetically inert titanocene dichloride with alcoholic solvent for the synthesis of quinazoline derivatives was developed. 1 mol% Cp2TiCl2 at 30 °C afforded 17 examples of quinazoline derivatives with yields of 95-98% in 7-12 minutes. Mechanistic experiments using in situ NMR and HRMS established that the coordination of ethanol to the titanocene moiety released the catalytic species [Cp2Ti(OCH2CH3)2].
- Luo, Yanlong,Wu, Ya,Wang, Yunyun,Sun, Huaming,Xie, Zunyuan,Zhang, Weiqiang,Gao, Ziwei
-
p. 66074 - 66077
(2016/07/26)
-
- Deep eutectic solvent mediated synthesis of quinazolinones and dihydroquinazolinones: Synthesis of natural products and drugs
-
A mild and greener protocol was developed to synthesize substituted quinazolinones and dihydroquinazolinones via deep eutectic solvent (DES) mediated cyclization with a series of aliphatic, aromatic, and heteroaromatic aldehydes in good to excellent yields. This greener strategy was further utilised to synthesize various quinazolinone natural products and drugs.
- Ghosh, Suman Kr,Nagarajan, Rajagopal
-
p. 27378 - 27387
(2016/04/04)
-
- Self-Assembled Nanoliposomes of Phosphatidylcholine: Bridging the Gap between Organic and Aqueous Media for a Green Synthesis of Hydroquinazolinones
-
Self-assembly of phosphatidylcholine in water creates liposomal nanoreactors for environmentally friendly synthesis of hydroquinazolinones by two- or three-component reactions, without the use of an extra catalyst or solvent. Recycling of the reaction medium and the absence of a need for other organic reagents are further advantages of this protocol.
- Tamaddon, Fatemeh,KazemiVarnamkhasti, MohammadTaghi
-
p. 2510 - 2514
(2016/10/20)
-
- PEG-SO3H as eco-friendly polymeric catalyst for the synthesis of 2,3-dihydroquinazolinones in water
-
A facile, efficient, green, and environmentally benign method is described for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones by direct cyclocondensation of 2-aminobenzamide with aldehydes or ketones in water using PEG-SO3H as an acidic catalyst under room temperature. This new method totally avoids the use of organic acids, toxic or expensive solvents and affording the corresponding product in good to excellent yields in this reaction.
- Huang, Guoli,Liu, Bo,Teng, Mingyu,Chen, Yegao
-
p. 453 - 458
(2016/10/18)
-
- Green protocol for synthesis of 2,3-dihydroquinazolin-4(1H)-ones: lactic acid as catalyst under solvent-free condition
-
Abstract: In the present work, lactic acid was used as novel, green catalyst for synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives via two distinct methods, including reaction of 2-aminobenzamide with aldehydes/ketones or isatoic anhydride with ammonium acetate and aldehydes in neat condition at 70?°C. The desired products were obtained in satisfactory yields. Short reaction time, easy workup, and more importantly environmental benignity are the most outstanding advantages of these procedures. Graphical Abstract: [Figure not available: see fulltext.]
- Zhaleh, Sara,Hazeri, Nourallah,Maghsoodlou, Malek Taher
-
p. 6381 - 6390
(2016/07/06)
-
- An ionic liquid catalyzed reusable protocol for one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one under mild conditions
-
An efficient protocol has been developed for the synthesis of 2,3-dihydroquinazolinone compounds from anthranilamide and aldehydes or ketones via ionic liquid catalyzed cyclization reaction. The reaction features high efficiency, shorter reaction duration, mild reaction conditions and inexpensive reagents. The catalyst was recovered and reused. The recyclability of ionic liquid resulted in excellent yields of products without loss of any catalytic activity.
- Nagarajan,Shaikh, Tanveer Mahamadali,Kandasamy, Elango
-
supporting information
p. 9693 - 9699
(2015/12/05)
-
- Organocatalysis by p-sulfonic acid calix[4]arene: A convenient and efficient route to 2,3-dihydroquinazolin-4(1H)-ones in water
-
An efficient and eco-friendly method is reported for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from the direct cyclocondensation of anthranilamide with aldehydes using p-sulfonic acid calix[4]arene (p-SAC) as a recyclable organocatalyst in excellent yields in water at room temperature. The catalyst was reusable without significant loss of catalytic efficiency. Operational simplicity, the compatibility with various functional groups, non-chromatographic purification technique, high yields and mild reaction conditions are the notable advantages of this procedure. Large scale reaction demonstrated the practical applicability of this methodology.
- Rahman, Matiur,Ling, Irene,Abdullah, Norbani,Hashim, Rauzah,Hajra, Alakananda
-
p. 7755 - 7760
(2015/02/19)
-
- Copper-Catalyzed Intramolecular C-C Bond Cleavage to Construct 2-Substituted Quinazolinones
-
An efficient method for a copper-catalyzed intramolecular C-C bond cleavage to construct 2-substituted quinazolinones has been developed. The C-C bond at the 2-position of 2,2-disubstituted-1,2,3,4-tetrahydroquinazolinone was selectively cleaved by a Cu/air catalytic system. The trend for the cleavage was dependent on the leaving group in the order of: alkyl > methyl > phenyl > substituted aryl. The process described herein provides an explanation for the mechanism of the reaction between substituted 2-halobenzamides and α-substituted arylmethanamines to construct 2-substituted quinazolinones, which were previously reported and limited to the construction of 2-arylquinazolinones. The C-C bond at the 2-position of 2,2-disubstituted-1,2,3,4-tetrahydroquinazolinones was selectively cleaved by a Cu/air catalytic system to construct 2-substituted quinazolinones. The trend for the cleavage of the C-C bond was dependent on the leaving group in the order of: alkyl > methyl > phenyl > substituted aryl.
- Hu, Ben-Quan,Wang, Li-Xia,Yang, Luo,Xiang, Jun-Feng,Tang, Ya-Lin
-
supporting information
p. 4504 - 4509
(2015/07/27)
-
- Metal-free aerobic oxidative C-N bond cleavage of tertiary amines for the synthesis of N-heterocycles with high atom efficiency
-
An efficient metal-free aerobic oxidative C-N bond cleavage of tertiary amines has been developed to construct N-heterocycles using molecular oxygen as the sole oxidant with high atom efficiency, in which all of the three alkyl groups in tertiary amines can be utilized and transformed into N-heterocycles. This journal is the Partner Organisations 2014.
- Chen, Xiuling,Chen, Tieqiao,Zhou, Yongbo,Han, Daoqing,Han, Li-Biao,Yin, Shuang-Feng
-
supporting information
p. 3802 - 3807
(2014/06/09)
-
- Eco-friendly syntheses of 2,2-disubstituted- and 2-spiroquinazolinones
-
Environmentally friendly methods were applied to prepare quinazolin-4(1H)-one derivatives in either aqueous or solventless medium from anthranilamide and a number of ketones. With dialkyl-substituted ketones, acetophenone and cycloalkanones, the ring closure proceeded smoothly under either aqueous or solventless conditions. With poorly water-soluble cycloalkanones, the ring closure was carried out under mechanochemical ball-milling conditions, in the presence of molecular iodine as catalyst. The environmentally friendly protocols applied resulted in the corresponding quinazolinones in quantitative yields.
- Mikls, Ferenc,Hum, Veronika,Fül?p, Ferenc
-
-
- Glycerol based ionic liquid with a boron core: A new highly efficient and reusable promoting medium for the synthesis of quinazolinones
-
A highly efficient and environmental benign procedure for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones via the condensation of carbonyl compounds with 2-aminobenzamide using a glycerol based ionic liquid with a boron core as a new and reusable promoting medium is described. A broad range of substrates including aldehydes and ketone were condensed with 2-aminobenzamide. All reactions are completed in short times and the products are obtained in good to excellent yields. The reaction medium could be recycled and reused several times without any loss of efficiency. Moreover, presented procedure has been applied successfully for the synthesis of some novel bis(pyrazolinone) derivatives.
- Safaei, Hamid Reza,Shekouhy, Mohsen,Shafiee, Vahid,Davoodi, Mansooreh
-
p. 139 - 144
(2013/04/24)
-
- Supported N-propylsulfamic acid on magnetic nanoparticles used as recoverable and recyclable catalyst for the synthesis of 2,3-dihydroquinazolin- 4(1H)-ones in water
-
An efficient and eco-friendly method is reported for the synthesis of 2-substituted-2,3-dihydroquinazolin-4(1H)-ones from direct cyclocondensation of anthranilamide with aldehydes and ketones using N-propylsulfamic acid supported onto magnetic Fe3O4 nanoparticles (MNPs-PSA) as a recoverable and recyclable nanocatalyst in good to excellent yields in water at 70 °C. The catalyst was readily separated using an external magnet and reusable without significant loss of their catalytic efficiency.
- Rostami, Amin,Tahmasbi, Bahman,Gholami, Hoshyar,Taymorian, Hajir
-
p. 211 - 214
(2013/06/26)
-
- Efficient synthesis of 2,3-dihydroquinazolin-4(1H)-ones using heterogeneous solid acid catalysts: Unexpected formation of 2,3-dihydro-2-(4-(tetrahydro-2H- pyran-2-yloxy)butyl)quinazolin-4(1H)-one
-
The heterogeneous solid acid catalysts Amberlyst-15 and silica-HClO 4 displays efficient catalytic properties for the synthesis of 2,3-dihydroquinazolin-4(1H)-ones from anthranilamide and various aldehydes/ketones under mild reaction conditions and in good yields. These catalysts also showed good catalytic activity for condensation of anthranilamide with a cyclic enol ether 3,4-dihydropyran and led to formation of new unexpected quinazolinone product 6 comprising two dihydropyran moieties. The new product 6 has been reported for the first time and is fully characterized using 2D-NMR data. Furthermore, both solid acid catalysts can be easily recycled without significant loss of activity. ARKAT-USA, Inc.
- Bharate, Sandip B.,Mupparapu, Nagaraju,Manda, Sudhakar,Bharate, Jaideep B.,Mudududdla, Ramesh,Yadav, Rammohan R.,Vishwakarma, Ram A.
-
p. 308 - 318
(2012/10/29)
-
- The divergent transformations of aromatic o-aminonitrile with carbonyl compound
-
A modified Friedlaender conversion of the cyclocondensation of aromatic o-aminonitriles with carbonyl compounds was discovered. Systematic studies reveal that both the new transformation and the classic Friedlaender annulation in the presence of ZnCl2 constitute a pair of divergent reaction, and thecontrolled PDF transformation of this divergent reaction was achieved in the present of bases.
- Tang, Jianhong,Li, Jiarong,Zhang, Lijun,Ma, Shuling,Shi, Daxin,Zhang, Qi,Yang, Liupan,Wang, Xiuzhen,Liu, Xuan,Liu, Change
-
experimental part
p. 533 - 542
(2012/08/27)
-
- New conditions for synthesis of (plusmn;)-2-monosubstituted and (plusmn;)-2,2-disubstituted 2,3-dihydro-4(1H)-quinazolinones from 2-nitro- and 2-aminobenzamide
-
An efficient synthesis of (plusmn;)-2-monosubstituted and (plusmn;)-2,2-disubstituted 2,3-dihydro-4(1H)-quinazolinones has been developed using a dissolving metal reduction-condensative cyclization strategy. Treatment of 2-nitrobenzamide and an aldehyde or ketone with iron powder in refluxing acetic acid affords high yields of the title compounds. More complex ring systems are available by incorporating additional reactive functionality γ to the carbonyl of the aldehyde or ketone substrate. The scope and limitations of the process along with optimized procedural details are presented. The same target molecules are also accessible by reaction of 2-aminobenzamide with aldehydes and ketones in refluxing acetic acid.
- Bunce, Richard A.,Nammalwar, Baskar
-
experimental part
p. 991 - 997
(2011/11/06)
-
- Sulfamic acid as a reusable and green catalyst for efficient and simple synthesis of 2-substituted-2,3-dihydroquinazolin-4(1H)-ones in water or methanol
-
A series of 2,3-dihydroquinazolin-4(1H)-ones have been synthesized in good to excellent yields through direct cyclocondensation of anthranilamide and aryl aldehydes or ketones in water or methanol under mild conditions. The reaction was efficiently promoted by 10 mol% sulfamic acid (SA, H2NSO 3H) and the catalyst could be recovered easily after the reactions and reused without evident loss of reactivity.
- Rostami, Amin,Tavakoli, Ashkan
-
experimental part
p. 1317 - 1320
(2012/01/12)
-
- Synthesis and biological activity of analogues of the antidiabetic/antiobesity agent 3-guanidinopropionic acid: Discovery of a novel aminoguanidinoacetic acid antidiabetic agent
-
3-Guanidinopropionic acid (1, PNU-10483) has been demonstrated to both improve insulin sensitivity and to promote weight loss selectively from adipose tissue in animal models of non-insulin-dependent diabetes mellitus (NIDDM). However, 1 has also been shown to be a substrate for both the creatine transporter and creatine kinase, leading to marked accumulation in muscle tissue as the corresponding N-phosphate 4. In an effort to identify novel entities that maintain antidiabetic potency without susceptibility to creatine-like metabolism, an analogue program was undertaken to explore the effects of various structural modifications, including homologation, simple substitution, single atom mutations, and bioisosteric replacements for the guanidine and carboxylic acid. Overall, the scope of activity encompassed by the set of new analogues proved to be exceedingly narrow. Notable exceptions demonstrating equivalent or improved antidiabetic activity included the α-amino derivative 29, aminopyridine 47, isothiourea 67, and aminoguanidine 69. On the basis of its superior therapeutic ratio, aminoguanidine 69 was selected for preclinical development and became the foundation for a second phase of analogue work. Furthermore, in vitro studies demonstrated that 69 is markedly less susceptible to phosphorylation by creatine kinase than the lead 1, suggesting that it should have less potential for accumulation in muscle tissue than 1.
- Larsen,Connell,Cudahy,Evans,May,Meglasson,O'Sullivan,Schostarez,Sih,Stevens,Tanis,Tegley,Tucker,Vaillancourt,Vidmar,Watt,Yu
-
p. 1217 - 1230
(2007/10/03)
-
- Definitive structural assignment of condensation products from anthranilamide and 3-amino-2-carbamoylthiophene with ketones. Formation of tetrahydroquinazolinones and their thiophene isosteres
-
Products formed from dehydrative cyclization of cyclopentanone, cyclohexanone, and cycloheptanone with anthranilamide (2) under neutral or acidic conditions are established as the spiro compounds 2,2-polymethylene- 1,2,3,4-tetrahydroquinazolin-4-ones 6 by means of (a) the presence of a 13C nmr signal at 66-79 ppm for atom C-2 and (b) X-ray crystallography on the tetramethylene compound 6a. Analogously, products from reactions of these cycloalkanones with 3-amino-2-carbamoylthiophene are now shown by 13C nmr spectra to have structures isosteric to 6, i.e. 5,5-polymethylene-4,5,6,7- tetrahydrothieno[2,3-e]pyrimidin-7-ones 5, rather than the chelate ring structures previously proposed. Additionally, conflicting literature reports on product 3 from reaction of acetone with 2 are partially clarified. Correlation of 13C chemical shifts in systems 3, 5, and 6 is presented.
- Klemm, LeRoy H.,Weakley, Timothy J. R.,Gilbertson, Robert D.,Song, Yang-Heon
-
p. 1269 - 1273
(2007/10/03)
-