Studies on Isocyanides and Related Compounds. Synthesis of 3‐Substituted 2‐Arylsulfonylamino‐3,4‐dihydro‐4‐oxoquinazolines via a Novel Three‐Component Reaction

The reaction between isocyanides 1,methyl anthranilate (2) and chloramines T (3a) or chloramines B (3b) occurred easily, in the presence of benzyltriethylammonium chloride to give the guanidines 4 which, upon heating, underwent a ring‐closure reaction to afford the title compounds 5.