Kleinpeter, E. (PhD)Tadessm, Tsegaye2018-06-262023-11-092018-06-262023-11-091984-06http://etd.aau.edu.et/handle/12345678/3645The reaction of W,N-Dimethylamides with the dimer of p-methoxyphenyl thionophosphine sulfide (Lawesson,' s reagent) gives N,N-Dimethylthioamides. BY treating these disubsti ... tuted thioamides with (i) the Vilsmeir -'Haack Arnold complex (formamide chloride) and (ii) Bis-(dimethylamino)tert- butoxy methane, mode1compounds (Me2N-CHPO(R)~~-NR2) ",ere synthesized. Substitution reactions \'1ere also carried: out using these model compounds (3-aminothioacrylamides) or their imi.nium salts with a primary amine (p-anisidine) to: synthesize the corresponding 3-anisidinothioacrylamides. The reactions were successful and yields \~ere nearly quantitative. The dynamic behaviour and the groUQdstate stereochemistry of these model compounds have been studied. Based on 1H_NMR study and LIS investigation, rotational barriers as well as' the preferred conformation of some of these model compounds have been determined from the proposed three dimensiona:t geometriesenThioacrylamideSThesis