Synthesis of isoquinolones and chemistry of few compounds

4-acetyl-1H-2-benzopyran-1, 3(4H)-dione was synthesized as an intermediate which was formed by the action of homophthalic anhydride on caproic anhydride in presence of pyridine as a catalyst. 4-acetyl-1H-2-benzopyran-1, 3(4H)-dione was directly treated with ammonia and primary amines to produce various isoquinolones. Later on the chemistry of 4-acetyl-1H-2-benzopyran-1, 3(4H)-dione was also discussed. We have also tried to establish the possible mechanism in the isoquinolone formation by carrying out various reactions and forming various products. We have also discovered in our research work that we get same isoquinolones by the action of ammonia and various primary amine with 3-methyl-1-oxo-1H-2-benzopyran-4-carboxylic acid, 3-methyl-1H-2-benzopyran-1-one or 4-acetyl-1H-2-benzopyran-1, 3(4H)-dione.