Compounds of Formula: (I); wherein: R.sup.1 is selected from: fluoro, chloro, C.sub.1-3alkyl and C.sub.1-3alkoxy; R.sup.2--X-- is selected from: methyl, methoxymethyl and Formula: (X); n is 0,1 or 2; or a salt, pro-drug or solvate thereof are described. Their use as GLK activators, pharmaceutical compositions containing them, and processes for their preparation are also described.