Microwave-assisted three component cyclocondensation reactions of aldehydes, amides and dienophiles in the presence of acetic anhydride and para-toluenesulfonic acid as a catalyst to afford the highly substituted cyclohexene derivatives, in relatively good yields after several minutes are reported.

Novel coumarin derivatives, 2-oxo-2H-chromenecarbaldehyde hydrazones were prepared by reaction of substituted 2-oxo-2H-chromenecarbaldehydes with N-aminoimides in ethanol in the presence of 4-toluenesulfonic acid as catalyst. The photochromic and thermochromic properties of the prepared compounds were investigated.

The multi-component solid form of febuxostat (FEB) with p-toluenesulfonic acid was synthesized by solvent-drop grinding and cooling-evaporative crystallization characterized powder X-ray diffraction (XRPD), thermogravimetry (TGA), differential scanning calorimetry (DSC), infrared spectroscopy (FT-IR). stable after exposure at elevated temperature relative humidity dissolution measurements revea...

This paper is aimed to estimate the transmittance of electronic effects in fluorescein molecule between phthalic acid residue and xanthene moiety. Despite almost orthogonal orientation latter with respect rest molecule, some influence substituents this 9-aryl ring on dissociation hydroxyl group hydroxyxanthene cannot be ruled out. In order reveal (possible) effect, we blocked carboxylic via est...