Dozens of hybrids of natural alkaloid evodiamine/rutaecarpine and thieno[2,3-d]pyrimidinones were synthesized in a straightforward method by condensation of substituted 2H-thieno[2,3-d][ 1 , 3 ]oxazine-2,4(1H)-diones or N-methyl-2H-thieno[2,3-d][ 1 , 3 ]oxazine-2,4(1H)-dione with