The invention provides antifungal agents of the formula: ##STR1## and their pharmaceutically acceptable salts, wherein R is phenyl optionally substituted by 1 to 3 substituents each independently selected from halo and CF.sub.3 ;R.sup.1 is C.sub.1 -C.sub.4 alkyl;R.sup.2 is H or C.sub.1 -C.sub.4 alkyl; and"Het", which is attached to the adjacent carbon atom by a ring carbon atom, is selected from pyridinyl, pyridazinyl, pyrimidinyl, pyrazinyl and triazinyl, "Het" being optionally substituted by C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, halo, CF.sub.3, CN, NO.sub.2, NH.sub.2, --NH(C.sub.1 -C.sub.4 alkanoyl) or --NHCO.sub.2 (C.sub.1 -C.sub.4 alkyl).