In the scope of a research program aiming at the synthesis of new nonsteroidal anti-inflammatory drugs (NSAIDs) acting on the enzymes of the arachidonic acid cascade, we describe in this paper the synthesis of two new series of functionalized alpha,beta-unsaturated 1,2-benzothiazin-3-one derivatives (3a-10a) and (3b-10b), structurally designed as dual cyclooxigenase-2 and 5-lipooxygenase inhibitors by applying rational principles of molecular modification and hybridization. The target compounds (3a-10a) and (3b-10b) were prepared in good overall yields, exploring as the key step of the synthetic route a Knoevenagel-Doebner condensation between substituted benzaldehydes (e.g. 4-methoxy-benzaldehyde) and corresponding 1,2-benzothiazin-3(4H)-one 1,1-dioxide derivatives (17a) and (17b).
1,2-Benzothiazin-3-one 1,1-dioxide derivatives; diastereoselective Knoevenagel-Doebner condensation; dual COX-2/5-LO inhibitors; NSAID candidates