7539-23-3Relevant articles and documents
Lewis acid–catalyzed green synthesis and biological studies of pyrrolo[3,4-c]pyrazoles in aqueous medium
Arjuna, Anania,Kaur, Manpreet,Singh, Baldev
, (2019/12/24)
An environmentally benign approach in aqueous medium by means of Lewis acid catalyst affords a wide spectrum of pyrazoline derivatives in satisfactory yields. [3+2] cycloaddition reactions of substituted azomethine-N-imines to maleimide in aqueous medium at relatively high concentrations of Lewis acid catalyst have emerged as an environment friendly alternative to conventional solvents. Promising catalytic activity has been revealed by Lewis acid like Cu (NO3)2 in aqueous medium. The obvious features of this synthetic protocol were short reaction time, high efficiency, less hazardous synthesis by benign solvent, catalysis, modest workup, and a clean reaction methodology.
Fe+3-montmorillonite K10 as an Efficient Reusable Heterogeneous Catalyst for the Grind Mediated Synthesis of 14-aryl-14H-dibenzo [a,j]xanthenes
Fekri, Leila Z.,Nikpassand, Mohammad,Fard, Hajar S.,Marvi, Omid
, p. 135 - 142 (2016/03/01)
Background: Xanthenes are an important class of organic compounds and have also received significant attention due to their wide range of pharmacological activities such as antibacterial, antiviral, antiinflammatory activities, antagonists for the paralyzing action of zoxazolamine and efficiency in photodynamic therapy, a well-known method for controlling the localized tumors. Natural sources are also rich of xanthene compounds. Popularly known pigments, santalin have been isolated from plant species. Furthermore, these compounds can be emerged as pH-sensitive fluorescent materials for visualization of biomolecules, in laser technologies and as dyes. There are several reports in the literature for the synthesis of xanthenes such as alkylations of heteroatoms, cyclodehydrations, cyclocondensations between 2-hydroxyaromatic aldehydes and 2- tetralone, trapping of benzynes by phenols and intramolecular phenyl-carbonyl coupling reactions of benzaldehydes and acetophenones bearing tethered carbonyl chains in the presence of hexamethylphosphoramide and SmI2. Other methods for the synthesis of xanthenes include the reaction of formamide with β-naphthol, carbon monoxide, and 1- hydroxymethyl-naphthalen-2-ol. Methods: procedure a: A mixture of substituted benzaldehyde, 2-naphtol and Fe+3-montmorillonite K10 was mixed. After completion of the reaction, the product was solved in CHCl3 (3×10 mL) and insoluble catalyst was removed by filtration. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. procedure b: A mixture of substituted benzaldehyde, phenylhydrazine and Fe+3-montmorillonite K10 were added to a mortar and the mixture was pulverized with a pestle. After completion of the reaction, 2-naphtol was added to the consulting mixture and pulverized with a pestle. The organic phase including the product and chloroform was evaporated under vacuum. The resulting crude material was purified by recrystallization from EtOH to afford pure products. Results: As part of our going interest for the development of efficient and environmentally friendly procedures for the synthesis of heterocyclic and pharmaceutical compounds, we wish to report the first grind mediated synthesis of some derivatives of xanthenes using catalytic amount of Fe+3-montmotillonite. Conclusion: In conclusion, we have investigated the Fe+3-montmorillonite K10 under grinding as a mild and efficient catalyst for the synthesis of substituted 14-aryl-14H-dibenzo [a,j]xanthenes. The remarkable advantages offered by this method are: catalyst is inexpensive, non-toxic, easy handling and reusability, simple work-up procedure, short reaction time, high yields of product with better purity and green aspect by avoiding toxic catalyst and hazardous solvent.
One-pot tandem synthesis of tetrasubstituted pyrazoles via 1,3-dipolar cycloaddition between aryl hydrazones and ethyl but-2-ynoate
Ningaiah, Srikantamurthy,Doddaramappa, Shridevi D.,Chandra,Madegowda, Mahendra,Keshavamurthy, Shubakara,Bhadraiah, Umesha K.
supporting information, p. 2222 - 2231 (2014/07/07)
1,3,4,5-Tetrasubstituted pyrazoles are rapidly and regioselectively synthesized in a one-pot, three-step sequence consisting of condensation, nitrilimine generation, and cycloaddition using mercuric acetate. Newly synthesized compounds were characterized by spectral studies. Regiochemistry of compounds 6a and 8a was determined as 1,4- and 1,5-regioisomers respectively by X-ray crystallography. Copyright