congeners were synthesized (see 1–25) and tested for affinity to sigma 1 and sigma 2 receptor subtypes, by displacing [3H]- (+)-pentazocine and [3H]DTG from guinea pig brain and rat brain preparations, respectively. All compounds exhibited a good affinity for the σ1 subtype, with subnanomolar Ki values for the best of them, while only modest or poor affinity for the σ2 subtype was observed (Tables 1 and 2)