"H2N-, R1L1 cannot contain amino; (d) when R1 is cyano, L1 must have more than 2 carbons; (e) R1L1 must contain at least 3 carbons; (f) where R1 and/or R2 is cycloheteroalkyl, such R1 and/or R2 is exclusive of substituted 1-piperidinyl, substituted 1-pyrrolidinyl, substituted 1-azetidinyl or substituted 1-(2-oxo-pyrrolidinyl); (g) where B is a heterocyclic ring and X is O, R1 and/or R2 are exclusiv" . . . .