Process for preparing and using guanidine derivatives

A process for preparing a compound having the following formula:

• ##STR60## wherein R is a substituted or unsubstituted hydrocarbon residue or acyl group;
• is an electron withdrawing group;
• Y.sup.1 and Y.sup.2, which are the same or different are each independently oxygen or sulfur;
• and A is a substituted or unsubstituted divalent hydrocarbon residue which comprises reacting a compound of the following formula:
• ##STR61## with a compound of the following formula:
• ##STR62## wherein Z.sup.1 and Z.sup.2, which are the same or different, are each halogen, or Z.sup.1 and Z.sup.2 taken together represent oxygen.