Synthesis of 5-heterocyclic substituted quinazolin-4-ones via 2-aminobenzonitrile derivatives

Two routes to prepare a series of six 5-heterocyclic substituted 2-chloro-7-methoxyquinazolin-4-ones are described, where the heterocycle is a substituted or unsubstituted 1-pyrazolyl, 5-pyrazolyl or 2-thiazolyl group. Both routes proceeded via key 2-aminobenzonitrile intermediates.