This document describes GB786234(A), which relates to improvements in substituted ureidocoumarin compounds and their use. It discloses new 3-phenyl-7-ureidocoumarin compounds that exhibit intensive blue to blue-green fluorescence, making them suitable as optical brightening agents. It also describes processes for producing these new compounds and using them to brighten organic materials like textiles. The key inventions are new 3-phenyl-7-ureidocoumarin compounds with the general formula (I) and methods of synthesizing them.