This invention relates to a new class of organic chemical compounds. More particularly, this invention is concerned with ester derivatives of N-trifluoroacetyl-N-phosphinothioylmethylglycine. This class of compounds has been found to be useful as intermediates in producing N-phosphinothioylmethylglycine esters which show herbicidal activity. Some of the class of compounds of this invention also show herbicidal activity when applied to certain varieties of weeds or undesired plants.