Rapid and Efficient Cascade Synthesis of 2‐Amino‐4(3 H)‐quinazolinones over an In Situ‐Generated Heterogeneous CuCO3–K2CO3 Nanocomposite

A green, recyclable, in situ-generated, heterogeneous CuCO3-K2CO3 nanocomposite-catalysed cascade reaction between 2-halobenzoic acids and guanidines is described for the synthesis of 2-amino-4(3H)-quinazolinones. The reaction is rapid and proceeds efficiently in air without the addition of a ligand or additive. This protocol is equally applicable to amidines for the synthesis of 2-alkyl- and 2-phenyl-4(3H)-quinazolinones.