1310417-73-2Relevant academic research and scientific papers
Regioselective Synthesis of Quinazolinone-/Phenanthridine-Fused Heteropolycycles by Pd-Catalyzed Direct Intramolecular Aerobic Oxidative C-H Amination from Aromatic Strained Amides
Banerji, Biswadip,Bera, Suvankar,Chatterjee, Satadru,Killi, Sunil Kumar,Adhikary, Saswati
, p. 3506 - 3512 (2016)
A new route for the expedient synthesis of specific regioisomer of quinazolinone- and phenanthridine-fused heterocycles through a palladium-catalyzed regioselective intramolecular oxidative C-H amination from cyclic strained amides of aromatic amido-amidine systems (quinazolinones) has been developed. The amine functionalization of an aromatic C-H bond from a strained amide nitrogen involved in aromaticity has been a challenging work so far. The fusion of two heterocyclic cores, quinazolinone and phenanthridine, can occur in two different ways (linear and angular), but under the conditions reported here, only linear type isomer is exclusively produced. This approach provides a variety of substituted quinazolinone- and phenanthridine-fused derivatives in moderate to excellent yields. Moreover, such fused molecules show excellent fluorescent properties and have great potential to be a new type of fluorophores for the use in medicinal and material science.
Access to 2-Arylquinazolin-4(3H)-ones through Intramolecular Oxidative C(sp3)?H/N?H Cross-Coupling Mediated by I2/DMSO
Wen, Simiaomiao,Du, Yifan,Liu, Yiwen,Cui, Xiaofeng,Liu, Qixing,Zhou, Haifeng
, (2021/12/01)
A novel approach for the synthesis of 2-arylquinazolin-4(3H)-ones was developed. A series of title compounds were obtained with good functional group tolerance and good yields by I2/DMSO-mediated intramolecular oxidative cross-coupling of 2-(benzylamino)benzamides to form C=N double bonds. This method was applicable for gram-scale synthesis. A proposed reaction pathway based on some control experiments was also provided.
Synthesis of quinazolin-4(3H)-ones via electrochemical decarboxylative cyclization of α?keto acids with 2-aminobenzamides
Tian, Qing,Wei, Yu,Xu, Liang,Zhang, Jinli
, (2021/01/05)
Herein, an environmentally benign electrochemical protocol has been disclosed for the synthesis of quinazolin-4(3H)-one derivatives from readily available α?keto acids and 2-aminobenzamides. This decarboxylative cyclization process proceeds conveniently in the absence of any homogeneous metal catalysts, bases, or external oxidants. This protocol also features CO2 by-products, mild reaction conditions (room temperature and air atmosphere), and a wide variety of substrate scope, including an array of 2,3-disubstituted quinazolinone products.
Electrochemical synthesis of quinazolinone: via I2-catalyzed tandem oxidation in aqueous solution
Hou, Huiqing,Ma, Xinhua,Lin, Yingying,Lin, Jin,Sun, Weiming,Wang, Lei,Xu, Xiuzhi,Ke, Fang
, p. 17721 - 17726 (2021/05/29)
The development of protocols for synthesizing quinazolinones using biocompatible catalysts in aqueous medium will help to resolve the difficulties of using green and sustainable chemistry for their synthesis. Herein, using I2 in coordination with electrochemical synthesis induced a C-H oxidation reaction which is reported when using water as the environmentally friendly solvent to access a broad range of quinazolinones at room temperature. The reaction mechanism strongly showed that I2 cooperates electrochemically promoted the oxidation of alcohols, then effectively cyclizing amides to various quinazolinones.
Electro-oxidative cyclization: Access to quinazolinones: Via K2S2O8without transition metal catalyst and base
Hou, Huiqing,Hu, Yongzhi,Ke, Fang,Sun, Weiming,Wu, Xianghua,Yu, Ling,Zhou, Sunying
, p. 31650 - 31655 (2021/11/30)
A K2S2O8-promoted oxidative tandem cyclization of primary alcohols with 2-aminobenzamides to synthesize quinazolinones was successfully achieved under undivided electrolytic conditions without a transition metal and base. The key feature of this protocol is the utilization of K2S2O8 as an inexpensive and easy-to-handle radical surrogate that can effectively promote the reaction via a simple procedure, leading to the formation of nitrogen heterocycles via direct oxidative cyclization at room temperature in a one-pot procedure under constant current. Owing to the use of continuous-flow electrochemical setups, this green, mild and practical electrosynthesis features high efficiency and excellent functional group tolerance and is easy to scale up.
Palladium(II) N^O Chelating Complexes Catalyzed One-Pot Approach for Synthesis of Quinazolin-4(3 H)-ones via Acceptorless Dehydrogenative Coupling of Benzyl Alcohols and 2-Aminobenzamide
Balaji, Sundarraman,Balamurugan, Gunasekaran,Ramesh, Rengan,Semeril, David
, p. 725 - 734 (2021/04/06)
A convenient protocol for the one-pot synthesis of quinazolin-4(3H)-ones using palladium(II) complexes via dehydrogenative coupling of readily available benzyl alcohols and 2-aminobenzamide has been described. New structurally related Pd(II) N^O chelating complexes of general configuration [Pd(L)Cl(PPh3)] (where L = dimethylamino benzoylhydrazone ligands) have been designed and synthesized. The formation of the complexes has been recognized by analytical and spectral methods (FT-IR, NMR, HR-MS). The presence of a square-planar geometry around the palladium(II) ion was confirmed by single crystal X-ray diffraction study. A wide range of substituted quinazolinones have been successfully achieved from a diverse range of benzyl alcohols in good to excellent yields using 1.0 mol % of catalyst loading under aerobic conditions. Furthermore, control experiments reveal that the dehydrogenative coupling reaction involves initially the formation of an aldehyde intermediate and subsequent formation of a cyclic aminal intermediate.
Zinc Stabilized Azo-anion Radical in Dehydrogenative Synthesis of N-Heterocycles. An Exclusively Ligand Centered Redox Controlled Approach
Das, Siuli,Mondal, Rakesh,Chakraborty, Gargi,Guin, Amit Kumar,Das, Abhishek,Paul, Nanda D.
, p. 7498 - 7512 (2021/06/30)
Herein we report an exclusively ligand-centered redox controlled approach for the dehydrogenation of a variety of N-heterocycles using a Zn(II)-stabilized azo-anion radical complex as the catalyst. A simple, easy-to-prepare, and bench-stable Zn(II)-complex (1b) featuring the tridentate arylazo pincer, 2-((4-chlorophenyl)diazenyl)-1,10-phenanthroline, in the presence of zinc-dust, undergoes reduction to form the azo-anion radical species [1b]- which efficiently dehydrogenates various saturated N-heterocycles such as 1,2,3,4-tetrahydro-2-methylquinoline, 1,2,3,4-tetrahydro-isoquinoline, indoline, 2-phenyl-2,3-dihydro-1H-benzoimidazole, 2,3-dihydro-2-phenylquinazolin-4(1H)-one, and 1,2,3,4-tetrahydro-2-phenylquinazolines, among others, under air. The catalyst has further been found to be compatible with the cascade synthesis of these N-heterocycles via dehydrogenative coupling of alcohols with other suitable coupling partners under air. Mechanistic investigation reveals that the dehydrogenation reactions proceed via a one-electron hydrogen atom transfer (HAT) pathway where the zinc-stabilized azo-anion radical ligand abstracts the hydrogen atom from the organic substrate(s), and the whole catalytic cycle proceeds via the exclusive involvement of the ligand-centered redox events where the zinc acts only as the template.
Copper-Catalyzed One-Pot Synthesis of Quinazolinones from 2-Nitrobenzaldehydes with Aldehydes: Application toward the Synthesis of Natural Products
Pal, Shantanu,Sahoo, Subrata
, p. 18067 - 18080 (2021/12/06)
A novel, efficient, and atom-economical approach for the construction of quinazolinones from 2-nitrobenzaldehydes has been unveiled via copper-catalyzed nitrile formation, hydrolysis, and reduction in one pot for the first time. In this reaction, urea is used as a source of nitrogen for nitrile formation, hydrazine hydrate is used for both the reduction of the nitro group and the hydrolysis of nitrile, and atmospheric oxygen is used as the sole oxidant. The method portrays a wide substrate scope with good functional group tolerances. Moreover, this method was applied for the synthesis of schizocommunin, tryptanthrin, phaitanthrin-A, phaitanthrin-B, and 8H-quinazolino[4,3-b]quinazolin-8-one.
Aerobic primary and secondary amine oxidation cascade by a copper amine oxidase inspired catalyst
Thorve, Pradip Ramdas,Maji, Biplab
, p. 1116 - 1124 (2021/02/26)
Herein, we report a bioinspired catalytic system for the one-pot cascade oxidation of a native primary amine and anin situgenerated non-native secondary amine. The catalyst consists of ano-quinone cofactor phd (1,10-phenanthroline-5,6-dione) and a copper ion and operates under ambient air conditions. Quinazolin-4(3H)-ones, which are common pharmacophores present in numerous pharmaceuticals and bioactive compounds, were synthesized in high yields. A detailed kinetic and mechanistic study elucidates the role of the catalyst in the multi-step oxidative cascade reaction.
Improved, gram-scale synthesis of sildenafil in water using arylacetic acid as the acyl source in the pyrazolo[4,3-d]pyrimidin-7-one ring formation
Laha, Joydev K.,Gulati, Upma,Saima,Gupta, Anjali,Indurthi, Harish Kumar
supporting information, p. 2643 - 2648 (2021/02/16)
An improved, gram-scale synthesis of the blockbuster drug sildenafil, used for the treatment of male erectile dysfunction, has been developed. Unlike the previous literature, the current method demonstrates the use of arylacetic acid as an acyl source, a cheap oxidant K2S2O8, and water as the reaction medium in the key step of pyrrazolo[4,3-d]pyrimidin-7-one ring formation. As well as being a green and benign approach, the current method reduces the cost by half compared to our previous strategy. In addition, the general relevance of the method has been demonstrated in the synthesis of a variety of quinazolinone and benzothiazole derivatives with excellent functional group tolerance.
