a number of 3-amino-1, 2, 4-triazin-5 (2h)- ones(1) were synthesized and condensed with a-haloketones to give 2,6-disubstituted imidazo [1, 2-b] [1, 2, 4]-triazin-3 (4h)-ones (2). these compounds were reacted further with a - haloketones to yield n-alkylated products (3).

silica-bonded n-propyltriethylene-tetramine (sbnptt) was found as an efficient solid base for the synthesis of 2-amino-5-oxo-5,6,7,8-tetrahydro-4h-chromenes. chromene derivatives were obtained via the three-component condensation reaction of aromatic aldehydes, malononitrile, and dimedone at 80 oc under solvent-free conditions. the heterogeneous solid base showed much the same efficiency when u...