Recurrent aseptic meningitis associated with herpes simplex virus type 2

4-Hydroxy-2-quinolones 139. Synthesis, structure, and antiviral activity of N-R-amides of 2-hydroxy-4-oxo-4H-pyrido[1,2-a]pyrimidine-3-carboxylic acids

“…The C (6) -C (7) 1.412 (2) In the pyridine fragment of amide 4d a tendency was observed towards the localization of bonds. The bond lengths of C (4) -C (5) 1.349(2) and C (2) -C (3) 1,365(2) Å were significantly shortened and the bonds C (3) -C (4) 1.418(2) and C (2) -C (1) 1.417(2) Å were lengthened. An analogous effect has also been noted in other pyridopyrimidines [17,18].…”

“…The C (12) -C (13) ethyl substituent occupies a position intermediate between -ac-and apr-conformations, but the C (14) -C (15) ethyl substituent is found in the +sc-conformation relative to the C (11) -C (10) bond (torsion angles C (12) -N (4) -C (11) -C (10) 155.9(1), C (14) -N (4) -C (11) -C (10) 80.7(2)°). The C (13) atom has an orientation close to +sc, but the C (15) has an orientation close to ap relative to the C (11) -N (4) bond (torsion angles C (11) -N (4) -C (12) -C (13) 75.9(2), C (11) -N (4) -C (14) -C (15) -160.0(2)°). Such a position of the ethyl groups leads to shortened intramolecular contacts -H (10b) ···C (14) The creation of effective and safe antiviral preparations is one of the most complex problems in contemporary pharmaceutical chemistry and medicine.…”