Synthesis and Analgesic Activity of Some 1-Benzofurans, 1-Benzothiophenes and Indoles

Abstract

3-Unsubstituted 1-benzofurans 1e and 1f , 3-methyl-1-benzofurans 1a - 1d , and 3-amino-1-benzofurans 2a - 2l , as well as 3-amino-1-benzothiophenes 3a , 3b and 3-aminoindoles 4a - 4f , 11a , and 11b were prepared and tested as analgesics. The 3-amino-1-benzofurans 2 were prepared from the corresponding 2-hydroxybenzonitriles 5 and phenacyl bromides 6 via intermediates 7 . Similar treatment of 2-sulfanylbenzonitrile ( 8 ) provided 3-amino-1-benzothiophenes 3 . Appropriately substituted 2-aminobenzonitriles 9 then provided N-substituted 3-aminoindoles 4 . 1-(Ethoxycarbonyl)indoles 4e and 4f were successfully deprotected giving indoles 11a and 11b , respectively.