| The compound of the formula: ##STR1## wherein R.sup.1 is H, alkyl or cycloalkyl of 1 to 6 carbon atoms;R.sup.2 is H, alkyl of 1 to 6 carbon atoms, cyano, halo, nitro, amino or mono or dialkylamino in which the alkyl groups have 1 to 6 carbon atoms;R.sup.3 is H or alkyl of 1 to 6 carbon a |
