A Novel Synthesis of Clonidine, an Anti-Hypertensive Drug from o-Chloronitrobenzene

Article abstract of DOI:10.1055/s-1987-27847

An elegant, cost-effective synthesis of clonidine (4) is reported from readily available starting materials. o-Chlorophenylhydroxylamine (2), obtained from o-chloronitrobenzene, is formylated to N-(2-chlorophenyl)-N-hydroxyformamide (3).In a one-pot procedure, 3 is converted to clonidine by chlorination with thionyl chloride and then with thionyl chloride/sulfuryl chloride, followed by condensation with ethylenediamine.