S33005 is a serotonin–norepinephrine reuptake inhibitor (SNRI) that was under development by Servier for the treatment of depression and related disorders.

It is structurally related to venlafaxine but has a more complex molecular structure.

Venlafaxine appears to be a sigma modulator,[1] but it is not known if S33005 shares this activity.

"The 1-cyano-benzocyclobutenes used as starting material are obtained, for example, by subjecting a β-[orthohalogeno-phenyl]-propionitrile to intramolecular condensation in the presence of potassium amide, or by brominating a benzocyclobutene in position 1 with N-bromosuccinimide, followed by exchange of the bromine atom for a cyano group by means of sodium cyanide.

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