N-acyl phosphonamidothioates and dithioates

A compound of the formula ##STR16## wherein:

• X is O or S;
• R is selected from the group C.sub.1 to C.sub.10 alkyl, C.sub.2 to C.sub.10 alkenyl, phenyl or C.sub.7 to C.sub.10 phenalkyl;
• R.sup.1 is selected from the group C.sub.3 to C.sub.6 alkyl, C.sub.3 to C.sub.6 alkenyl, phenyl or C.sub.7 to C.sub.10 phenalkyl;
• R.sup.2 is selected from the group C.sub.1 to C.sub.10 alkyl, C.sub.2 to C.sub.10 alkenyl, C.sub.2 to C.sub.10 alkynyl, C.sub.1 to C.sub.10 haloalkyl, C.sub.3 to C.sub.10 alkoxycarbonylalkyl, C.sub.9 to C.sub.10 (alkoxycarbonyl)(phenyl) alkyl, phenyl, naphthyl, C.sub.7 to C.sub.10 phenalkyl and C.sub.8 to C.sub.10 phenalkenyl;
• and
• R.sup.3 is selected from the group C.sub.1 to C.sub.3 alkyl and C.sub.1 to C.sub.3 haloalkyl.