Synthesis of 4(3<i>H</i>)‐quinazolinones from derivatives of methyl 2‐isothiocyanatobenzoate

Abstract

Abstract Ethyl N ‐(2‐methoxycarbonylphenyl)thiocarbamate ( 2), N ‐(2‐ethoxycarbonylphenyl)‐4‐methoxythiobenz‐amide ( 3b ), and 2‐(4‐methoxyphenyl)‐4 H ‐3,1‐benzothiazin‐4‐one ( 4a ), react with nucleophilic reagents containing at least one primary amino group to yield a variety of 2‐substituted and 2,4‐disubstituted 4(3 H )quinazolinones, as well as some tricyclic and tetracyclic products.