Synthesis and spectroscopic studies of substituted 5,6,7,8-tetrahydroquinazolin-2-amine compounds via one-pot method

Abstract 5,6,7,8-Tetrahydro derivatives of quinazoline-2-amine have been synthesized and characterized. These reactions, which are carried out using one-pot multicomponent reactions (MCR's), proceed more easily than conventional multistep organic reactions. This method allows new organic molecules to be synthesized in a single step with minimum time and number of trials. Cyclocondensation of each of the previously substituted hetaryl carboxaldehydes with cyclic ketones and guanidine carbonate was achieved by the technique of MCR; and structures of all the synthesized compounds 6-methyl-4-(thiophen-2-yl)-8-(thiophen-2-ylmethylidene)-5,6,7,8-tetrahydroquinazolin-2-amine (4f) , 6-methyl-4-(3-methyl-thiophen-2-yl)-8-[(3-methylthiophen-2-yl)methylidene]-5,6,7,8-tetrahydroquinazolin-2-amine (4g) , 6-methyl-4-(5-methylthiophen-2-yl)-8-[(5-methylthiophen-2-yl)methylene]-5,6,7,8-tetrahydroquinazolin-2-amine (4h) , 4-(thiophen-2-yl)-8-(thiophen-2-ylmethylidene)-5,6,7,8-tetrahydroquinazolin-2-amine (4i), 4-(3-methylthiophen-2-yl)-8-[(3-methylthiophen-2-yl)methylidene]-5,6,7,8-tetrahydroquinazolin-2-amine (4j) and 4-(5-methylthiophen-2-yl)-8-[(5-methylthiophen-2-yl)methylidene]-5,6,7,8-tetrahydroquinazolin-2-amine (4k) have been determined and characterized by infrared, nuclear magnetic resonance, mass spectral data and elemental analysis. All the new synthesized compounds were evaluated for their antibacterial activity.