Synthesis of 3-amino-2-methyl/ethyl-5,6,7,8-tetrahydro[1]benzothieno[2,3-<i style="">d</i>] pyrimidin-4(3<i style="">H</i>)-one and its Schiff bases as possible antimicrobial and non-steroidal antiinflammatory agents <b style=""> </b>

Abstract

Ethyl 2-amino-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate <b style="">1</b> has been converted into ethyl 2-(acetylamino)-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate <b>2a</b> and ethyl 2-(propionylamino)-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate <b style="">2b</b>. Compounds <b>2a</b> and <b>2b</b> on treatment with hydrazine hydrate give 3-amino-2-methyl-5,6,7,8-tetrahydro[1]benzothieno[2,3<i>-d</i>]pyrimid-4(3<i style="">H</i>)-one <b style="">3a</b> and 3-amino-2-ethyl-5,6,7,8-tetrahydro[1]benzothieno[2,3<i>-d</i>]pyrimid-4(3<i style="">H</i>)-one <b style="">3b</b> respectively. Compounds <b style="">3a</b> and <b style="">3b </b>have been treated with aromatic aldehydes to get Schiff bases <b style="">4a-l</b> and <b style="">5a-l</b>. The compounds have been characterized by spectral analysis and screened for antibacterial and antifungal activity. Eight compounds have also been screened for their antiinflammatory activity. A few of the compounds exhibit promising biological activity.