| Abstract: | The Suzuki cross‐coupling reaction was found effective for rapid access to a series of 3,4‐diarylisoxazoles of pharmacological interest. The efficiency of this approach was demonstrated by the synthesis of the highly potent COX‐2‐selective inhibitor, 4‐(5‐methyl‐3‐phenyl‐4‐isoxazolyl)benzenesulfonamide (valdecoxib), and its analogues. Thus, the coupling reaction between (3‐aryl‐5‐methyl‐4‐isoxazolyl)boronic acids, prepared in situ from the corresponding bromides using triisopropyl borate, and aryl bromides containing a 4‐sulfonamide or 4‐methylsulfonyl group under the standard conditions Pd(PPh3)4, Na2CO3, EtOH‐H2O, reflux] yielded the target 3,4‐diarylisoxazoles in good yields. |
