Abstract Homophthalic acid (1) undergoes reaction with 1, 2-, 1, 3-, and 1, 4-diamines to give condensed 1 (2H)-isoquinolinones like 2, 4, 13, and 25, which exhibit marked enamine character. These are attacked by electrophiles at the N or C terminus. Some notable reactions of imidazoisoquinolone 2 are those with maleic and acrylic acids to form the tetracycles 48 and 51, respectively. With propiolic acid, 5 underwent an interesting ...
