Xylamidine

Xylamidine is a drug which acts as an antagonist at the 5HT_2A receptor, and to a lesser extent at the 5HT_1A receptor. It does not cross the blood–brain barrier, which makes it useful for blocking peripheral serotonergic responses like cardiovascular and gastrointestinal effects, without producing the central effects of 5HT_2A blockade such as sedation, or interfering with the central actions of 5HT_2A agonists.

Synthesis

Xylamidine is an amidine which serves as a serotonin inhibitor. This agent is prepared by alkylation of 3-methoxyphenol (m-methoxyphenol) with α-chloropropionitrile, KI and potassium carbonate in MEK to give #, which is in turn reduced with lithium aluminum hydride to give the primary amine #. When # is treated with m-tolylacetonitrile in the presence of anhydrous HCl, the synthesis is completed. Alternately, one can react primary amine # with m-tolylacetamidine under acid catalysis to produce xylamidine.