Acta Pharm. 58 (2008) 359-378
Original research paper
Synthesis and evaluation of analgesic,
anti-inflammatory and ulcerogenic activities of some triazolo- and 2-pyrazolyl-pyrido[2,3-d]-pyrimidines
HEND N.
HAFEZ, HEBAT-ALLAH S. ABBAS and ABDEL-RAHMAN B. A. EL-GAZZAR
National Research Centre, Photochemistry Department
(Heterocyclic Unit), Dokki, 12622 Cairo, Egypt
Accepted Septemeber 18,
2008
New series of 2-hydrazino-7,8-dihydro-6H-cyclopenta[5,6]pyrido[2,3-d]pyrimidines
and its 1,7,8,9-tetrahydrocyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidine,
1,7,8,-9-tetrahydrocyclopenta[5,6]pyrido[2,3-d][1,2,3,4]tetrazolo[4,5-a]pyrimidine,
8,9-dihydro-7H-cyclopenta[5,6]pyrido[2,3-d]imidazolo[1,2-a]pyrimidine,
2-(pyrazol-1-yl)-7,8-dihydro-6H-cyclopenta[5,6]pyrido[2,3-d]pyrimidine
derivatives were prepared in order to obtain new compounds with potential
anti-inflammatory and analgesic activity and low ulcerogenic effect. The compounds
possessing potent anti-inflammatory activity were further tested for their
analgesic and ulcerogenic activities. Compounds 3-amino-6-(4-aryl)-9-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(H)-one
(4c), 1-amino-2-methyl-6-(4-aryl)-9-(4-aryl-methylene)-cyclopenta[5,6]pyrido[2,3-d]imidazolo[1,2-a]pyrimidin-5(H)-one
(6a), 2-amino-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d]pyrimidine-4(H)-one
(9), 2-(3-amino-5-hydroxypyrazol-1-yl)-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]-pyrido[2,3-d]pyrimidin-4(H)-one
(10a) and 3-thioxo-6-(4-aryl)-9-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d][1,2,4]triazolo[4,3-a]pyrimidin-5(H)-one (13)
showed significant analgesic effects. Compound 2-(3-amino-5-hydroxypyrazol-1-yl)-5-(4-aryl)-8-(4-arylmethylene)-cyclopenta[5,6]pyrido[2,3-d]pyrimidin-4(H)-one
(10a) was evaluated as the lead compound having higher anti-inflammatory
activity (82.8%) than ibuprofen (79.5%) and lower ulcerogenic effect.
Keywords: pyrido[2,3-d]pyrimidines,
[1,2,4]triazole anellation, anti-inflammatory activity, analgesic activity