Wyniki wyszukiwania - BazTech

Ograniczanie wyników

1 Polish Journal of Chemistry

1 1999

Znaleziono wyników: 1

Liczba wyników na stronie

Wyniki wyszukiwania

Sortuj według:

Ogranicz wyniki do:

Crystal and molecular structures of three anxiolytic pyrazolopyridines

Kubicki M., Codding P.

Polish Journal of Chemistry

1999

vol. 73 nr 4

693-706

The crystal structures of three pyrazolopyridines, ethyl 4-amino-6-ethyl-1-pentyl-1H-pyrazolo[3,4-b]pyridinum-5-oate chloride hydrate C16H25N4O2+ × Cl- (2), and 4-amino-1-pentyl-1H-pyrazolo[3,4-b]pyridine-5-N-(2-propenyl)carboxamide C15H21N5O (3) have been determined by X-ray structure analysis of single crystals. The ethyl and isopropyl substituents in compounds 1 and 2, respectively, which are in ortho position relative to the ester group, cause a twist of the O=C-O-C plane with respect to the plane of pyrazolopyridine ring system. In the absence of that steric hindrance, in compound 3, the intramolecular N(amine)-H…O hydrogen bond closes the nearly planar six-membered ring. The coplanarity of the ester or amide plane with the plane of ring system is probably a necessary condition for the significant anxiolytic action. In both cations, the protonation takes place at the pyridine nitrogen atom. In the crystal structures of salts there are separate layers of anions and cations. In the free base, intermolecular hydrogen bonds make infinite chains of molecules.