Synthesis of 2,3-tetramethylene-5-arenesulfonamidobenzofurans
The reaction of N-arenesulfonyl-1,4-benzoquinonimines with 1-morpholino(piperidino)-1-cyclohexene gives 2,3-dihydro-2-morpholino(piperidino)-2,3-tetramethylene-5-arene-sulfonamidobenzofurans. Refluxing of the latter in dilute hydrochloric acid gave 2,3-tetramethylene-5-arenesulfonamidobenzofurans, the structure of which was proved by hydrolysis to 2,3-tetramethylene-5-aminobenzofuran and conversion of it to the previously described 2,3-tetramethylene-5-hydroxybenzofuran.