one of these compounds , 5,6-dihydro-8,9,11,12-tetramethoxy-1,3-dioxo-1h-benz [ f ] - isoquino [ 8,1,2- hij ] quinazoline-2 ( 3h ) -carboxylic acid , ethyl ester ( 9 ) , is amongst the most potent and selective compounds of this class yet identified .
C0007066
carboxylic acid
C0014898
ester