A series of pyrroloquinazolines has been discovered that represent novel small molecule inhibitors of the intramolecular ligand of the thrombin receptor. Analogs were prepared to study the structure-activity relationships of substitution at the N1, N3, and N7 positions of the heterocycle. Compounds 4e and 4f have been identified with IC50's of 56 and 52 nM, respectively. (C) 1999 Elsevier Science Ltd. All rights reserved.