Efficient synthesis of pyrido[2,3-d]pyrimidine-7-carboxylic acids catalyzed by a TiO2/SiO2 nanocomposite in aqueous media at room temperature

2018 ◽  
Vol 73 (9) ◽  
pp. 641-645 ◽  
Author(s):  
Sepehr Sadegh-Samiei ◽  
Shahrzad Abdolmohammadi

AbstractA novel and efficient synthesis of eight 5-aryl-1,3-dimethyl-2,4-dioxo-1,2,3,4,5,8-hexahydropyrido[2,3-d]pyrimidine-7-carboxylic acids using a TiO2/SiO2 nanocomposite with a molar ratio of 1:1 as a recyclable heterogeneous catalyst is described. The desired products, five of which are new, are formed in short reaction times (2–3 h) with high to excellent yields (94%–98%) under very moderate reaction conditions (room temperature, aqueous media).

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Hamzeh Kiyani ◽  
Fatemeh Ghorbani

Abstract2-Amino-4-aryl-4H-benzo[h]chromenes and 3-amino-1-aryl-1H-benzo[f]chromenes were prepared by treating cyano-methylene compounds (malononitrile or ethyl cyanoacetate), substituted aromatic aldehydes, and naphtholic compounds in the presence of potassium phthalimide as a green, mild, efficient, and commercially available organocatalyst in aqueous media. The procedure was readily conducted and affords remarkable advantages such as safety, short reaction times, environmentally benign milder reaction conditions, no organic solvent required, and high yields.


Synthesis ◽  
2019 ◽  
Vol 51 (08) ◽  
pp. 1832-1840 ◽  
Author(s):  
Svetlana Amosova ◽  
Andrey Filippov ◽  
Vladimir Potapov ◽  
Maxim Penzik ◽  
Nataliya Makhaeva ◽  
...  

Regio- and stereoselective ring-opening reaction of 2-bromomethyl-1,3-thiaselenole with thiols proceeded as nucleophilic attack at the selenium atom of seleniranium intermediate affording unsaturated selanyl sulfides, (Z)-CH2=CHSCH=CHSeSR, in up to 93% yield. Dithiols were involved in this reaction giving symmetrical polyunsaturated compounds with two S–Se bonds in 70–75% yields. Efficient synthesis of 2-(organylsulfanyl)-2,3-dihydro-1,4-thiaselenines in 69–96% yields was developed by the acid-catalyzed cyclization of the unsaturated selanyl sulfides. Mild reaction conditions (room temperature) and short reaction times are important features of this methodology.


RSC Advances ◽  
2021 ◽  
Vol 11 (26) ◽  
pp. 15989-16003
Author(s):  
Milad Kazemnejadi ◽  
Mohammad Ali Nasseri ◽  
Safoora Sheikh ◽  
Zinat Rezazadeh ◽  
Seyyedeh Ameneh Alavi Gol

A highly efficient, robust, and green protocol has been developed for the synthesis of acridine and quinazoline derivatives in water under mild reaction conditions using a Fe3O4@Sap/Cu(ii) nanocomposite as an efficient heterogeneous catalyst.


2020 ◽  
Vol 56 (96) ◽  
pp. 15165-15168
Author(s):  
Nicolás Ríos-Lombardía ◽  
Luciana Cicco ◽  
Kota Yamamoto ◽  
José A. Hernández-Fernández ◽  
Francisco Morís ◽  
...  

Faster, milder, greener…better! The Meyer–Schuster rearrangement is disclosed for the first time in a deep eutectic solvent, namely FeCl3·6H2O/glycerol (3 : 1), enabling the reaction at room temperature, under air and with short reaction times.


Synthesis ◽  
2018 ◽  
Vol 51 (02) ◽  
pp. 522-529 ◽  
Author(s):  
Deqing Shi ◽  
Lingna Wang ◽  
Tiancong Ma ◽  
Mingming Qiao ◽  
Qiangxian Wu ◽  
...  

A visible-light photoredox-catalyzed oxidation/[3+2] cycloaddition/oxidative aromatization cascade reaction of [(3,4-dihydroisoquinolin-2(1H)-yl)methyl]phosphonates and activated olefins or alkynes for the efficient synthesis of potentially biological active pyrrolo[2,1-a]isoquinoline-substituted phosphonates was developed. This transformation features mild reaction conditions (i.e., visible light irradiation, room temperature), molecular oxygen (O2) as a green oxidant, simple ‘one-pot’ operation.


2019 ◽  
Vol 15 ◽  
pp. 874-880
Author(s):  
Razieh Navari ◽  
Saeed Balalaie ◽  
Saber Mehrparvar ◽  
Fatemeh Darvish ◽  
Frank Rominger ◽  
...  

An efficient approach for the synthesis of pyrazolopyridines containing the aminochromane motif through a base-catalyzed cyclization reaction is reported. The synthesis was carried out through a three-component reaction of (arylhydrazono)methyl-4H-chromen-4-one, malononitrile, primary amines in the presence of Et3N at room temperature. However, carrying out the reaction under the same conditions without base led to a fused chromanyl-cyanopyridine. High selectivity, high atom economy, and good to high yields in addition to mild reaction conditions are the advantages of this approach.


2011 ◽  
Vol 396-398 ◽  
pp. 1283-1286
Author(s):  
Jian Peng Zhu ◽  
Chun Hu Li ◽  
Jia Ling Chen ◽  
Ying Wei Luo

Abstract. Investigation of polymer resin as catalyst in the oxidative desulfurization (ODS) process has revealed that the method can be applied to make a relative high removal of sulfur compounds. The reaction conditions, including temperature, amount of oxidant and reaction time were studied. The best result occurs under mild conditions with respect to room temperature and atmospheric pressure, to remove 75.54% of the totle sulfur content in the presence of H2O2 with an O/S molar ratio of 17. Possible mechanism is also disscussed.


2016 ◽  
Vol 40 (6) ◽  
pp. 5053-5060 ◽  
Author(s):  
Shweta Kumari ◽  
Amiya Shekhar ◽  
Devendra D. Pathak

GO–TiO2 has been found to be a highly efficient and recyclable heterogeneous catalyst for the synthesis of pyrazoles and pyridines in aqueous medium at room temperature.


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