The synthesis of methyl 2-[(3,3-diethylthioureido)phenylmethylamino]-3-methylbutyrate and -4-methylpentenoate 3 have been achieved from 3-(chlorophenylmethylene)-1,1-diethylthiourea and the methyl esters of L-valine and L-leucine. From the latter, a bis-derivative 4 was also obtained as minor reaction product. Other compounds with morpholine residues and the glycine derivatives 5 have also been prepared