Synthesis of substituted benzothieno[3,2-c]isoquinolin-5(6H)-ones and their sulfinyl and sulfonyl derivatives

An approach to the synthesis of substituted benzothieno[3,2-c]isoquinolin-5(6H)-ones with good yields was suggested, which consists of the condensation of substituted 2-mercaptobenzo-nitriles with methyl 2-(chloromethyl)benzoate and subsequent treatment of the condensation products obtained with potassium tert-butoxide. The oxidation of the condensation products to sulfoxides or sulfones and subsequent treatment of these compounds with potassium tert-butoxide led to substituted benzothieno[3,2-c]isoquinolin-5(6H)-one 11-oxides or substituted benzothieno[3,2-c]isoquinolin-5(6H)-one 11,11-dioxides with good yields.