A novel, simple and environmentally friendly method is reported for the preparation of 1,8-dioxo-octahydroxanthene derivatives by the reaction of dimedon with various aromatic aldehydes, using thiamine chloride  as a recyclable catalyst under solvent-free conditions. This procedure has following benefits; simple workup, moderate reaction times, good yields, and completely compatible with enviro...

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 ...

An efficient green route for the preparation of naphthoxazinones, applying a three-component one-pot condensation reaction of 2-naphthol, aromatic aldehyde and urea in the presence of nano silica supported ferric chloride under solvent-free conditions has been developed. The present procedure offers several advantages such as short reaction time, simple workup, recovery and reusability of the c...

For the first time B-podands have been studied as an efficient and powerful catalysts in the ring opening of epoxides with azide anion in water. The reaction afforded the corresponding 1,2-azidoalcohols with high regioselectivity under mild reaction conditions and in a highly atom economic fashion.

A novel, simple and environmentally friendly method is reported for the preparation of 1,8-dioxo-octahydroxanthene derivatives by the reaction of dimedon with various aromatic aldehydes, using thiamine chloride  as a recyclable catalyst under solvent-free conditions. This procedure has following benefits; simple workup, moderate reaction times, good yields, and completely compatible with enviro...

an efficient and simple one-pot approach for the synthesis of 3,4-dihydropyrimidin-2-(1h)-one derivatives using antimony trichloride (sbcl3) as a mild catalyst by means of three-component biginelli reaction between β-keto esters, aldehyde derivatives and urea/thiourea under thermal and solvent-free conditions with excellent yields and short reaction times is reported. this methodology offers se...

selectfluor [1-(chloro methyl) -4-flouro -1,4-di azonia bicyclo[2,2,2] octane bis (tetraflouro-borate)] catalyzed the preparation of quinoxaline and 2,3-dihydo pyrazine derivatives through one -pot condensation of 1,2-di amines with 1,2-di carbonyls in solvent and under solvent- free conditions. this catalyst is commercially available, inexpensive, reusable, stable to air and moisture, and rela...

sulfonic acid functionalized sba-15 (sba-pr-so3h) as a new nanoporous acid catalyst was used in the one-pot synthesis of polyhydroquinolines derivatives via the hantzsch four component condensation reaction of aldehydes, b-ketoesters, dimedone and ammonium acetate under solvent free conditions with short reaction time in excellent yields. sba-pr-so3h was proved to be an efficient heterogeneous ...

1-carboxymethyl-3-methylimidazolium chloride {[cmmim]cl} is utilized as a highly efficient and reusable catalyst for the synthesis of bis(indolyl)methanes by the condensation reaction of indole with arylaldehydes under solvent-free conditions at room temperature. in summary, the presented method have several advantages including simplicity, low cost, generality, efficiency, clean reaction profi...

The demonstration by Nelson and Mayer (1949) of an antibody in syphilitic sera that immobilizes virulent Treponema pallidum in the presence of complement in vitro led to the development (Nelson and Mayer, 1949; Nelson and Diesendruck, 1951) of a T. pallidum immobilization (TPI) test for use in the case of individuals who might repeatedly give a positive reaction to other tests for syphilis but ...