title: Synthesis and antiallergy activity of 10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidines and 10-oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidines.
abstract: Synthesis and antiallergy activity of 10-oxo-10H-pyrido[1,2-a]thieno[3,2-d]pyrimidines (2 and 3) and 10-oxo-10H-pyrido[1,2-a]thieno[3,4-d]pyrimidines (4 and 5) are described. The activity, shown by these compounds in the rat passive cutaneous anaphylaxis (PCA) test, is compared to the PCA data previously reported for a series of 4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidines. 10-Oxo-N-1H-tetrazol-5-yl-10H-pyrido[1,2-a]thieno[3,4-d]pyri midine (2b), 10-oxo-7-(1H-tetrazol-5-yl)-10H-pyrido[1,2-a]thieno[3,4-d]py rimidine (4e), and 3,10-dihydro-10-oxo-7-(1H-tetrazol-5-yl)-1H-pyrido[1,2-a]thieno[3, 4-d] pyrimidine (7e) gave a 100% inhibition in the rat PCA test at a dose of 5 mg/kg. The activity displayed by these compounds is comparable to that of the most active compounds in the 4-oxo-4H-pyrido[1,2-a]thieno[2,3-d]pyrimidine series.
mesh_terms: D000818:Animals; D001681:Biological Assay; D006634:Histamine H1 Antagonists / Q000138:chemical synthesis*; D007202:Indicators and Reagents; D010323:Passive Cutaneous Anaphylaxis; D011725:Pyridines / Q000138:chemical synthesis*; D011743:Pyrimidines / Q000138:chemical synthesis*; D051381:Rats; D013329:Structure-Activity Relationship; D013876:Thiophenes / Q000138:chemical synthesis*
chemical_list: D006634:Histamine H1 Antagonists; D007202:Indicators and Reagents; D011725:Pyridines; D011743:Pyrimidines; D013876:Thiophenes