Synthesis of new 4-aryl-isoxazolo[5,4-<i style="">d</i>]pyrimidin-6-one(thione) and 4-aryl-pyrazolo[3,4-<i style="">d</i>]-pyrimidin-6-one derivatives of potential antihypertensive activity

2091-2098Some aromatic aldehydes are subjected to react with urea (or thiourea) and acetyl acetone in a one-pot Biginelli-type cyclocondensation reaction to give 5-acetyl-4-aryl-6-methyl-1,2,3,4-tetrahydro-pyrimidines 2a-j. Aldehydes with ortho-hydroxy substituent namely salicylaldehyde and 2-hydroxy-3-methoxybenzaldehyde undergo Michael-type addition of the hydroxyl-proton to the C5-C6 double bond of the pyrimidine ring to form the tricyclic derivatives 3a-d while 2-hydroxy-3-nitrobenzaldehyde reacted normally to give 2j. Compounds from the type 2 react with basic hydroxylamine to give the respective isoxazolopyrimidine derivatives 4a-g through an intramolecular addition of the oxim-hydroxyl proton to the C5-C6 double bond of the pyrimidine ring. The oxime derivatives from the tricyclic compounds 3a,c undergo rupture of the oxacyclic ring followed by addition of the oxim-proton to the C5-C6 double bond of the pyrimidine ring giving rise to the corresponding isoxazolophenols 5a,b. Furthermore, when hydrazine hydrate reacts with the acetyl derivatives 2a, 2f and 2h afford the corresponding 4-aryl-5-(1-hydrazono-ethyl)-6-methyl-3,4-dihydro-1H-pyrimidin-2-one 6a-c, while the compounds 2d and 3c react under the same reaction conditions to give the pyrazolopyrimidine derivatives 7 and 8, respectively

CAAD | INNOVATION | PRACTICE: 6th International Conference Proceedings of the Arab Society for Computer Aided Architectural Design

The concepts and applications of Computer Aided Architectural Design (CAAD) have a predominant presence and impacts on human innovation and creativity. ASCAAD society invites academics, researchers and professionals interested in CAAD concepts, practical impacts on human innovation and traditional design thinking, products, processes or organizations to join and contribute to the debate on learned lessons from the past, present and potential future impacts of present and future CAAD on innovation