Melamine trisulfonic acid (MTSA) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2H-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...

Various types of aldehydes undergo crossed-Aldol condensation with ketones in the presence of melamine trisulfonic acid (MTSA) under solvent-free conditions. The reported method is mild, efficient and has the advantages such as using heterogeneous catalysis, short reaction times, high yields of the products and the recyclability of the catalyst.

Melamine trisulfonic acid (MTSA) as an efficient heterogeneous catalyst has been used for the one-pot preparation of triazolo[1,2-a]indazole-1,3,8-trione and 2H-indazolo[2,1-b]phthalazine-1,6,11-trione derivatives by the three-component condensation reaction of urazoles or phthalhydrazide, dimedone or 1,3-cyclohexanedione, and aldehydes under solvent-free conditions in good to excellent yields ...

The effect of the aerosol phase (solid versus aqueous) on the heterogeneous OH oxidation of succinic acid (C4H6O4) is investigated using an aerosol flow tube reactor. The molecular and elemental transformation of the aerosol is quantified using Direct Analysis in Real Time (DART), a soft atmospheric pressure ionization source, coupled to a high-resolution mass spectrometer. The aerosol phase, c...

The oleic acid-ozone heterogeneous reaction system: products, kinetics, secondary chemistry, and atmospheric implications of a model system – a review J. Zahardis and G. A. Petrucci Department of Chemistry, University of Vermont, Burlington, VT 05405-0125, USA Received: 18 October 2006 – Accepted: 26 October 2006 – Published: 9 November 2006 Correspondence to: G. A. Petrucci (giuseppe.petrucci@...

nano silica sulfuric acid as a solid acid, was described to be an effective catalyst for one-pot three-component reaction of kojic acid, aryl aldehydes and indoles for the preparation of 2-substituted aryl (indolyl) kojic acid derivatives. the catalyst was prepared by combination of chlorosulfonic acid to nano silica gel. the size of nanoparticles were observed with sem.all prepared compounds w...

Mesoporous carbonaceous materials have outstanding potential in many different applications such as adsorption, medicine and catalysis. We have recently reported the synthesis of a new form of mesoporous carbon, named Starbon®, obtained after low temperature carbonization of expanded starch. Such starch-derived mesoporous materials have several tunable properties including surface energies (ran...

the one-pot, multi-component synthesis of 4,4′-(arylmethylene)bis(1h-pyrazol-5-ols) by tandem knoevenagel-michael reaction of phenylhydrazine, ethyl acetoacetate and aldehydes in the presence of silica-bonded n-propylpiperazine sulfamic acid (sbppsa) as a recyclable solid acid catalyst was reported. sbppsa showed much the same efficiency when used in consecutive reaction runs.

Silica sulfuric acid as an efficient and reusable heterogeneous catalyst has been used for the preparation of amidines 2 from formimidate 1 by reaction with aromatic amines at room temperature in good to excellent yields. Imidate was prepared by treatment of equimolar quantities of triethyl orthoformate and diaminomaleonitrile in refluxing dioxane. All the compounds were characterized fully by ...