Chemistry of lofexidine.

The systematic syntheses and pharmacological studies of numerous imidazolines aryloxyalkyl-substituted in the 2-position show that substitution of the aryl residue in the 2,6-position by halogen and addition of a side-chain to the alkyl residue results in compounds with marked antihypertensive activity. 2-[1-(2,6-Dichlorphenoxy)-ethyl-2-imidazoline hydrochloride (lofexidine, Lofetensin and Loxacor) exhibits the most marked hypotensive activity. The synthesis and physico-chemical properties of lofexidine are described.