Phenylethynyl and styryl derivatives of imidazole and fused ring heterocycles

This invention relates to the treatment of mGluR5 receptor mediated disorders, which comprises administering to a person in need of treatment a compound having the formula ##STR1##

wherein R¹, R², R³, R⁴ and R⁵ are as defined in the description, A signifies -CHCH- or -CC-; and B signifies ##STR2##

wherein R⁶ to R²⁶, X and Y are as defined herein.