A general one-pot synthesis of dibenz[b,f][1,4] oxazepine-11(10H)-carboxamides is described. The Ugi four-component reaction (U-4CR) of 2-aminophenols, cyclohexyl isocyanide, 2-chloro-5-nitrobenzaldehyde, and 2-bromobenzoic acids in MeOH in the presence of 25 mol% Mg(ClO4)2 at 30-40 .C for 22-95 h gave the linear Ugi products. The latter were treated with aqueous K2CO3 in MeOH under microwave heating at 120 .C for 10 min for promoting the intramolecular nucleophilic aromatic substitution (SNAr), affording the 6/7/6-fused tricyclic heterocycles in 61-85% yields.
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