One-pot multistep synthesis of 3,4-fused isoquinolin-1(2H)-one analogs

Abstract We have developed a robust approach for the synthesis of 3,4-fused isoquinolin-1( 2H )-one analogs. A benzonitrile or a nicotinonitrile bearing an ortho -substituent, such as –OH, –SH, or –NHR (R = alkyl or aryl) can be deprotonated by KO t Bu and then reacted with methyl 2-(bromomethyl)benzoate ( 8 ) to form its corresponding O-, S-, or N-alkylation product. The product thus formed is then treated with KO t Bu again to initiate a cascade process that will lead to the formation of its corresponding 3,4-fused isoquinolin-1( 2H )-one. This multistep synthesis as well as the final product purification is achieved in a one-pot manner.