An efficient synthesis of the novel microtubule inhibitor STA-5312 (3-[(4-cyanophenyl) methyl]-N-(3-methyl-5-isothiazolyl)-α-oxo-1-indolizineacetamide) was developed. A novel DMF/Me2SO4 directed regioselective synthesis of the 3-(4-cyanobenzoyl)-indolizine (4) was a critical transformation within the four-step process. Alternatively, a CuCl mediated synthesis of 3-(4-cyanobenzyl) indolizine (5) was also developed. All intermediates were ...