Synthesis, crystal structure, and BSA interaction with a new Co(II) complex based on 5-(trifluoromethyl)pyridine-2-carboxylic acid

The crystal structure of 5-(tri-fluoro-meth-yl)picolinic acid monohydrate reveals a water-bridged hydrogen-bonding network

The title compound [systematic name: 5-(tri-fluoro-meth-yl)pyridine-2-carb-oxy-lic acid monohydrate], C7H4F3NO2·H2O, is the acid hydrate of a pyridine with a carb-oxy-lic acid group and a tri-fluoro-methyl substituent situated para to one another on the aromatic ring. The mol-ecule forms a centrosymmetric water-bridged hydrogen-bonding dimer with graph-set notation R 4 4 (12). Hydrogen-bonding distances of 2.5219 (11) and 2.8213 (11) Å are observed between the donor carb-oxy-lic acid and the bridging water acceptor, and the donor water and carbonyl oxygen acceptor, respectively. The dimers are further linked into a two-dimensional sheet via two longer inter-molecular hydrogen-bonding inter-actions between the second hydrogen atom on the bridging water mol-ecule and both a pyridine nitro-gen atom and carbonyl oxygen with distances of 3.1769 (11) and 2.8455 (11) Å, respectively. The tri-fluoro-methyl groups extend out the faces of the sheet providing for F⋯F and C-H⋯F contacts between the sheets, completing the three-dimensional packing.

Pyridine-2-carboxylic acid as an effectual catalyst for rapid multi-component synthesis of pyrazolo[3,4-b]quinolinones

Green synthesis of pyrazolo[3,4-b]quinolinones was designed using bioproduct pyridine-2-carboxylic acid (P2CA) as a green and efficient catalyst. The multi-component reaction of aldehydes, 1,3-cyclodiones and 5-amino-1-phenyl-pyrazoles regioselectively produced pyrazolo[3,4-b]quinolinones in excellent yield (84–98%). Recyclization of the catalyst was also investigated. The electronic effect of the various substituents in aromatic rings indicated that the reaction proceeded through the carbocation intermediate. This newly designed protocol very quickly constructed products conventionally under milder conditions.

Green synthesis of pyrazolo[3,4-b]quinolinones was designed using bioproduct pyridine-2-carboxylic acid (P2CA) as a green and efficient catalyst.