Synthesis of 2-Amino 3-Substituted Quinazolin-4(3H)-one DerivativesviaIodine-Mediated Guanidinylation of Pbf-Activated Thiourea

2-Amino 3-substituted-quinazolin-4(3H)-one derivatives were synthesized from Pbf-isothiocyanate and methyl anthranilate. The construction of the guanidine-containing quinazolinone heterocyclic skeleton was achieved using Pbf-activated thiourea treated with primary amines via iodine-mediated guanidinylation. The desired compounds were obtained after Pbf cleavage by trifluoroacetic acid.