scholarly journals One-Pot Synthesis of Coumarins Unsubstituted on the Pyranic Nucleus Catalysed by a Wells–Dawson Heteropolyacid (H6P2W18O62)

Author(s):  
Yu-Feng Sun ◽  
Jia-Meng Liu ◽  
Jing Sun ◽  
Ya-Tao Huang ◽  
Jia Lu ◽  
...  

The development of a method to produce coumarins unsubstituted on the pyranic nucleus catalyzed from Wells–Dawson heteropolyacid (H6P2W18O62), phenol derivatives and ethyl 3,3-diethoxypropionate using Pechmann condensation under solvent-free conditions is described. This catalytic method was also applied successfully to synthesize various substituted coumarins, including the corresponding phenols and ethyl 3,3-diethoxypropionate. This work provides a novel, cheaper and safer way to syhthesize coumarins unsubstituted on the pyranic nucleus.

1999 ◽  
Vol 23 (9) ◽  
pp. 574-575
Author(s):  
Firouz Matloubi Moghaddam ◽  
Mohammad Ghaffarzadeh ◽  
Seyed Hossein Abdi-Oskoui

An AICl3–ZnCl2 mixture supported on silica gel is found to be an efficient medium for the Fries rearrangement of acyloxybenzene or naphthalene derivatives in solvent-free conditions under microwave irradiation.


2010 ◽  
Vol 2 (2) ◽  
pp. 337-342 ◽  
Author(s):  
P. Rajput ◽  
N. J. P. Subhashini ◽  
Shiva Raj

A series of 2,4,6-triarylpyridines have been prepared using a variety of aromatic and heteroaromatic aldehydes in the presence of aluminum phosphate (AlPO4) as a heterogeneous catalyst at 120 oC under solvent-free conditions. The present methodology offers several advantages such as excellent yields, simple procedure, shorter reaction times, milder conditions and the catalyst exhibited remarkable reusable activity. Keywords: Aluminum phosphate; 2,4,6-triarylpyridines; One-pot synthesis; Shorter reaction times;  Reusable activity.  © 2010 JSR Publications. ISSN: 2070-0237 (Print); 2070-0245 (Online). All rights reserved. DOI: 10.3329/jsr.v2i2.3859               J. Sci. Res. 2 (2), 337-342 (2010) 


2011 ◽  
Vol 76 (11) ◽  
pp. 1307-1315 ◽  
Author(s):  
Behrooz Maleki ◽  
Hafezeh Salehabadi ◽  
Zeinalabedin Sepehr ◽  
Mina Kermanian

A simple and benign protocol has been explored for the preparation of 2,4,6-triarylpyridines by a one-pot reaction between aryl aldehydes, enolizable ketones and ammonium acetate in the presence of N-bromosuccinimide or trichloroisocyanuric acid as green and neutral catalysts. The reactions proceed smoothly at 130 °C under solvent-free conditions to provide 2,4,6-triarylpyridines in good yields.


2004 ◽  
Vol 33 (9) ◽  
pp. 1168-1169 ◽  
Author(s):  
J. S. Yadav ◽  
S. Praveen Kumar ◽  
G. Kondaji ◽  
R. Srinivasa Rao ◽  
K. Nagaiah

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