scholarly journals Facile Condensation of Aromatic Aldehydes with Chroman-4-ones and 1-Thiochroman-4-ones Catalysed by Amberlyst-15 under Microwave Irradiation Condition

2011 ◽  
Vol 8 (2) ◽  
pp. 863-869 ◽  
Author(s):  
Tapas K. Mandal ◽  
Rammohan Pal ◽  
Rina Mondal ◽  
Asok K. Mallik
Keyword(s):  
Microwave Irradiation ◽  
Aldol Condensation ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
High Yield ◽  
Irradiation Condition ◽  
Free Condition ◽  
Amberlyst 15 ◽  
Solvent Free Condition

Different aromatic aldehydes and cinnamaldehyde undergo cross-aldol condensation with chroman-4-ones and1-thiochroman-4-ones in the presence of amberlyst-15 under microwave irradiation in solvent free condition to afford rapidly the correspondingE-3-arylidene andE-3-cinnamylidene derivatives, respectively, in high yield. This process is simple, efficient and environmentally benign.

Regeneration of Ketones from Semicarbazones in the Solid State on Wet Silica Supported Sodium Bismuthate under Microwave Irradiation

1999 ◽  
Vol 23 (5) ◽  
pp. 320-321
Author(s):  
Alok Kumar Mitra ◽  
Aparna De ◽  
Nilay Karchaudhuri
Keyword(s):  
Solid State ◽  
Microwave Irradiation ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Simple Method ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Sodium Bismuthate

Microwave irradiation of ketosemicarbazones on wet silica supported sodium bismuthate under environmentally benign solvent-free condition provides a fast, efficient and simple method for regeneration of ketones in good yields.

scholarly journals ACETYLATION OF ANISOLE IN GREEN CHEMISTRY CONDITIONS

2010 ◽  
Vol 13 (2) ◽  
pp. 62-70
Author(s):  
Thu Thi Hoang ◽  
Phuong Hoang Tran ◽  
Thach Ngoc Le
Keyword(s):  
Green Chemistry ◽  
Acetic Anhydride ◽  
Microwave Irradiation ◽  
Solvent Free ◽  
High Yield ◽  
Free Condition ◽  
Solvent Free Condition ◽  
Bismuth Triflate ◽  
Short Time ◽  
New Generation

In this study, acetylation of anisole by acetic anhydride, catalyzed by bismuth triflate are described. The reaction was taken place under new generation monomode microwave irradiation (Discover oven), solvent-free condition. High yield was obtainted in short time. Good selectivities for the para- products were observed. Bismuth(III) triflate could be recycled and reused effectively.

Green Synthesis and Biological Study of Pyrimidone derivatives employing Cetyltrimethyl ammonium bromide under solvent free condition

2021 ◽  
Vol 25 (11) ◽  
pp. 38-40
Author(s):  
S.R. Jagtap ◽  
R.P. Yadav ◽  
B.B. Bahule ◽  
D.J. Chaudhari
Keyword(s):  
Condensation Reaction ◽  
Biginelli Reaction ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
Biological Study ◽  
Ammonium Bromide ◽  
Solvent Free Condition ◽  
Cetyltrimethyl Ammonium ◽  
Anti Fungal

In this study, we are reporting a solvent free Biginelli reaction using aromatic aldehydes, ethyl acetoacetate and urea in presence of cetyl tri-methyl ammonium bromide as a catalyst. The reaction is green and environmentally benign. The yield of three component condensation reaction is excellent. The products were screened for anti-bacterial and anti-fungal activity. The method is simple and convenient. The catalyst is novel and easily available, non-expensive and nontoxic.

scholarly journals A Facile Solvent Free Synthesis of 3-arylidenechroman-4-ones Using Grinding Technique

2012 ◽  
Vol 9 (3) ◽  
pp. 1251-1256 ◽  
Author(s):  
Suresh Kumar ◽  
Jagdish K. Makrandi
Keyword(s):  
Polyphosphoric Acid ◽  
Cold Water ◽  
Aromatic Aldehydes ◽  
Solvent Free ◽  
Environmentally Benign ◽  
High Yield ◽  
Solvent Free Conditions ◽  
Microwave Irradiations ◽  
Grinding Technique ◽  
Solvent Free Synthesis

An efficient method for the synthesis of 3-arylidenechroman-4-ones has been developed under solvent free conditions using grinding technique. Grinding of variously substituted chroman-4-ones with aromatic aldehydes in presence of anhydrous barium hydroxide at room temperature give 3-arylidenechroman-4-ones in high yield (75-92%). Products are obtained by just acidification of the reaction mixture in ice cold water. Reaction in solid state, with enhanced rate, high selectivity and manipulative simplicity are the attractive features of this environmentally benign protocol. The chroman-4-one derivatives required for the reaction have been obtained by polyphosphoric acid (PPA) catalysed cyclisation of phenoxypropanoic acids under microwave irradiations.

DBU Catalysis: An Efficient Synthetic Strategy for 5,7-disubstituted-1,2,4- triazolo[1,5-a]pyrimidines

2020 ◽  
Vol 17 (1) ◽  
pp. 73-80
Author(s):  
Yogesh K. Pandey ◽  
Anu Mishra ◽  
Pratibha Rai ◽  
Jaya Singh ◽  
Jagdamba Singh ◽  
...  
Keyword(s):  
Ethyl Acetate ◽  
Solvent Free ◽  
High Yield ◽  
Reduced Pressure ◽  
Free Condition ◽  
Organic Layers ◽  
Solvent Free Condition ◽  
Synthetic Strategy ◽  
Significant Motif ◽  
Anhydrous Na2so4

Aim and Objective: An efficient and facile DBU catalysed synthesis of highly significant motif 5,7-disubstituted-1,2,4-triazolo[1,5-a]pyrimidines under solvent-free condition has been reported. Materials and Methods: To a round bottom flask, 1.0 mmol of chalcone (1), 1.5 mmol of 3-amino-1,2,4- triazole (2) and 30 mol% of DBU were added at 70 °C and stirred in solvent-free condition. After the completion of the reaction (monitored by TLC), water (10 ml) was added. The aqueous layer was extracted with ethyl acetate (3 ×10 ml). The combined organic layers were dried over anhydrous Na2SO4. The combined organic layers were evaporated under reduced pressure and the resulting crude product was purified by column chromatography by using ethyl acetate and hexane as eluent. Results: Reaction using chalcone and 3-amino-1,2,4-triazole as model substrates were carried out under different reaction conditions and it was observed that 30 mol% of DBU under the solvent-free condition at 70 °C was the optimum temperature for the proposed synthesis. Conclusion: Use of DBU (an organocatalyst) as a base, operational simplicity, high yield of products and short reaction time are some of the significant advantages associated with the proposed strategy.

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