This invention discloses new chemical compounds of the formula ##STR1## wherein R.sup.1 is selected from the group consisting of hydrogen, alkyl and alkenyl; R.sup.2 is selected from the group consisting of alkyl, alkenyl, cycloalkyl and ##STR2## WHEREIN Z is selected from the group consisting of alkyl, alkenyl, alkoxy, halogen, nitro and alkylthio; p is an integer from 0 to 5; and m is the integer 0 or 1; X.sup.1 and X.sup.2 are each selected from the group consisting of hydrogen, alkyl and halogen; Y is selected from the group consisting of oxygen and sulfur; n is the integer 1 or 2; and R.sup.3 and R.sup.4 are each alkyl.